What is the tekhelet that scholars, rabbis, and theologians are attempting to identify?
The smoke hovering over the battlefield of the “tekhelet debate” has billowed for centuries.
Around fifteen hundred to two thousand years ago the color and the source of the ancient biblical blue, known as tekhelet, was lost. The Jewish people have longed for its rediscovery. Scholars have searched for its identity.
There is one ancient substance that can pass the test as originating from a kosher source as well as being able to pass the Talmudic test of being a permanent, colorfast blue dye. It was the substance that initially excited the P’til Tekhelet foundation as being part of the Murex dye extraction. It was a substance used in ancient Egypt as well as in ancient Israel.
It is the ancient woad.
This article will attempt to demonstrate that the tekhelet of the book of Numbers was produced from woad (Isatis tinctoria) which, after the vast import of dyes from India, eventually became replaced by Indigofera tinctoria. Because of the impermanent nature of Indigofera dye, as well as its unclean manufacturing method, the early rabbis began searching for a purer, more permanent dye. This need was met by the Murex snail (or the cuttlefish according to others). The impermanence of Indigofera tinctoria, which early rabbis referred to as Kela-ilan, was of such major concern that it was considered wrong to use it for tekhelet. Methods of testing the colorfastness of dye were utilized in determining if a dye could be used for tekhelet. The identity of woad dye as tekhelet, however, had been lost in the shuffle.
Woad, which produces a permanent dye superior to Indigofera, was used by the ancients. Woad is identical in color and chemical composition to the dye of the Murex snail and Kela-ilan (Indigofera tinctoria), but passes all tests as a colorfast dye from a kosher source.
The symbolism of this substance and how it is manufactured hold deep symbolic and spiritual meaning.
Tekhelet (Hebrew: תכלת ) is the Hebrew transliteration for the word “blue” describing a specific dye to be used in the Temple of God and on the garments of his people. This blue dye is mentioned 48 times in the Jewish Bible (Tanakh) but was translated as hyakinthinos (Greek: ὑακίνθινος, blue) by the Septuagint version of the Bible. The uses of the dye included the clothing of the High Priest, the tapestries in the Tabernacle (Mishkan), and a thread, or threads, on the corner tassels of the tallit (ones garment and/or prayer shawl).
The instructions for using the tekhelet on the tassels of the tallit appear in the book of Numbers:
“And the LORD spake unto Moses, saying, “Speak unto the children of Israel, and bid them that they make them fringes in the borders of their garments throughout their generations, and that they put upon the fringe of the corners a ribband, a thread of blue: And it shall be unto you for a fringe, that ye may look upon it, and remember all the commandments of the LORD, and do them ; and that ye seek not after your own heart and your own eyes, after which you used to follow harlotry. Then you will remember to obey all my commands and will be consecrated to your God.”
Source of the Dye
The garment worn by Jews today as a prayer shawl is known as the “tallit.” It is traditionally made of wool, which has ribbons of blue (or black) on the borders of the garment and tassels on the four corners of the garment. The tassels are white. Originally one to four threads of each of the tassels was to be dyed blue. Rabbinical Jews maintain that only a specific dye — the original blue — may be used in dying these threads. At some point after the loss of the second Temple the exact identity of tekhelet — the blue of the Bible — became lost. Not knowing the exact identity of the biblical blue, rabbinical Jews have been wearing white tassels only on their garments, but long for the day when they can once again keep the sacred commandment to wear the tekhelet on their garments. A number of attempts to identify the tekhelet have resulted in some interesting theories.
The Bible (Torah) simply states that the material must be blue. Sources after the destruction of the second Temple attempts to identify “which blue” by identifying the source of the dye. According to rabbinical tradition the tekhelet is derived from a source called the Chilizon.
The chilazon, the source from which the tekhelet dye was obtained according to rabbinic tradition, is described in the Talmud. We are told its body is the color of the sea, its form is that of a fish, it appears every seventy years (or every seven years according to Masechet Tzitzt), its blood is used for tekhelet, and it is expensive.
Rabbi Gershon Henoch Leiner embarked on an extensive research program in 1887 and found the Sepia officinalis (Common Cuttlefish) to meet many of the above Talmudic criteria. This new tekhelet produced from the cuttlefish quickly caught on among the Rabbi’s followers and within one year, 10,000 Radziner Hassidim wore the colored tzitzit. The dye soon became popular also with Breslover Hassidim.
It was later discovered that the blue produced from the cuttlefish did not come from the fish itself but was a by-product of the cuttlefish fluid reaction to iron filings. Some felt the dye had to come from the creature itself, so more research ensued.
Rav Herzog’s doctoral research on the subject of the tekhelet, attempted to demonstrate that the Murex trunculus was the genuine “Chillazon”. However, he failed to consistently achieve blue dye from the small blue snail. In 2002 Dr. S.W. Kaplan of Rehovot, Israel proclaimed that he was able to dye wool with the extract of Janthina. To date this claim has not been substantiated.
The Murex trunculus, a sea snail, is the currently accepted source of the tekhelet dye. The first Chief Rabbi of Israel, Rabbi Yitzhak Halevi Herzog, wrote his doctoral thesis in 1913 on the tekhelet and named the Murex snail as the most likely candidate for the source of the dye. The Murex fulfilled many of the Talmudic criteria, but his inability to consistently obtain blue dye from the snail became a major obstacle. However, in the 1980’s a chemist, Otto Elsner, discovered that if a solution of the dye was exposed to sunlight, blue instead of purple was consistently produced. In 1993, the Ptil Tekhelet Foundation was formed for mass production of this tekhelet, as well as to continue further research.
Although the Murex sea snail is currently advanced as the source of the coveted dye, many are uneasy with the fact that the dye is obtained from an unclean or non-kosher animal.
The Bible (Torah) says that “all that have not fins and scales in the seas, and in the rivers, of all that move in the waters, and of any living thing which is in the waters, they shall be an abomination unto you” (Lev.11:10) It further tells us that “ye shall have their carcases in abomination.” According to these verses sea creatures such as the Murex snail, the cuttlefish, or Janthina were an “abomination” and even their carcasses were to be considered an “abomination” and anyone simply touching them became unclean.
Rabbeinu Bachyei insisted that only kosher species may be used for the mishkan. The Gemara states that “only items that one may eat may be used for the work of Heaven.” Nachmanides, Torah scholar and famed Jewish theologian, emphasized that the commandment concerning unclean animals pertained also to temple services.
Of course one could argue that the blue color of the resultant dye from the cuttlefish was totally due to the iron filings, “salts” and acids that were added to the fluid extract of the cuttlefish, therefore after the dye was extracted from the fluid the remaining dye was clean. One could also argue that since the fluid from the Murex snail is nothing more than the precursor to the dye, that once the resultant dye is extracted from the fluid of the snail that the dye is kosher. However, anything simply touching the unclean became unclean in itself, so that presents another problem. How would one even determine if all of the animal fluid had been removed?
Would the Torah devote so much time and effort describing unclean animals and the resultant polluting of oneself by touching them and then turn right around and command the use of unclean animal fluid to sanctify the mishkan and the ztit-ztits? Many do not think so.
So if indeed these creatures are considered non-kosher, unclean animals, than what should one use for the tekhelet? How about Indigofera tinctoria?
The Talmud mentions a counterfeit dye from a plant called Kela-ilan, known today as Indigofera tinctoria. The Talmud explains that it is absolutely forbidden to use this counterfeit dye intentionally but if one was duped, the threads are still kosher, however they simply do not fulfill the religious requirement for tekhelet strings.
Indigofera tinctoria is identified by most authorities as Kela-ilan (also see Nimukei Yosef Baba Metziah 34a), however indigo was most often mixed with other substances including the dye dibromo-indigo. It was traditionally made by mixing Indigofera with urine and allowing it to rot and ferment.
One prohibition for wearing the Kela-ilan resulted because some were hypocritically feigning to be wearing the more expensive, authentic tekhelet (R. Twerski. Pg 102, n.62). This would be similar to taking off the hood ornament of a Volkswagen and replacing it with the ornament of a Mercedes Benz and parading it around town to those who could not afford a Mercedes. Also true techelet was very expensive, and unscrupulous dealers made much money selling the counterfeit Kela-ilan.
However, the major reason that Kela-ilan was unsuitable was because it was not a steadfast dye.
Talmudic references gave specific tests in order to determine if the tekhelet is valid. These chemical tests were developed by the Sages to determine if the dye was fit to be used as the tekhelet (see Menachot 43a, Rashi and Rambam).
Woad and the Murex Snail
The most practical Murex snail dying technique required a fermenting vat for the process. However, this required modern chemicals that ancients would not have had access to. This presented a great obstacle.
Then a breakthrough discovery provided the answer. In 1995, Dr. Cardon found and translated a 1418 Florentine recipe for a vat process that used an indigoid plant called woad. Woad could be used in processing the blue dye from the Murex snail. This technique involved fermentation. Woad leaves were placed into hot alkaline water and allowed to set for awhile, and then the resulting liquid became capable of reducing indigo. Research revealed that this fermentation process was not purely chemical but rather microbiological.
The “P’til Tekhelet” foundation learned about the breakthrough and requested John Edmonds of England, a retired engineer who had been interested in ancient dyeing for years, to attempt to repeat the process.
Unfortunately when Mr. Edmonds found that woad fermentation brings its own indigo in, he felt it obscured the results of how much indigo that Murex contributed. So, he turned to fermentation from cockles’ meat.
Had they continued with woad they would have not only discovered a most ancient method of creating a steadfast dye but they would have realized the true nature of tekhelet.
Woad in Ancient Egypt
Woad, or dyer’s woad, comes from Isatis tinctoria L., a member of the mustard family, the Brassicaceae. Isatis contains some 30 species of biennial or perennial herbs, distributed from the Mediterranean to central Asia. Isatis tinctoria is native to Europe, North Africa and western Asia.  Woad is occasionally known as Asp of Jerusalem.
Scholars of spectral and photophysical research inform us that “The natural indigo plant source woad, Isatis tinctoria, was known throughout Europe and the Middle East as far back as the time of the ancient Egyptians, who used it to dye the cloth wrappings applied for the mummies.”  Skelton writes “Many early dyes were discovered by the ancient Egyptians, such as blue woad (Isatis tinctoria).”  Woad dye has been found on cloth of about 2500 BC and on later mummy wrappings. One source tells us, “Two Greek papyri found in Egypt, and studied by Pfister and other scholars, mention the use of a limited number of local dye sources for dying wool [including] Isatis tinctoria (woad).” 
Formerly various blue dyed fabrics discovered in ancient Egypt were thought to be Indigofera but A. Lucas informs us, “What has been assumed to have been Indian Indigo on ancient Egyptian fabrics may have been woad.”  According to one source “indigotin, probably derived from the leaves of the woad plant, was used by the ancient Egyptians as early as the 18th Dynasty .” 
An ancient tassel discovered in Qumran is now believed to have been dyed with woad.  This find predates the Talmud, it’s reflections on the chilizon, and the appearance of the kela-ilan problem. This appears to indicate that woad was indeed the original tekhelet of the Jewish people.
Roberts poses the question, “Which of the following – ceramic pot, silk yarn, glass, woad or wheel – has the oldest archaeological record?” Her answer is that fired pottery is the oldest but continues to say, “Surprisingly, woad comes second, long before the wheel, silk or glass; mankind was storing woad seeds in the Stone Age, possibly as early as 7,000 years ago. Fragments of blue-coloured linen or hemp found caught in an implement at a cave site in Adaouste in Southern France were dated to the Neolithic, while the inhabitants of other Neolithic sites were storing woad seeds.” 
The children of Israel were delivered from Egypt, the very nation which utilized the dye from woad. Would it not make perfect sense to deduce that the Israelites had knowledge of woad also?
Which Blue is True?
The original command to use tekhelet came from the Torah which does not specify what source tekhelet is to be derived from. We do know they had just been delivered from Egypt which had a history of using woad for blue dye. We are also informed that they wandered in the desert for many years where it would have been impossible to fish for sea snails.
The only source that really attempts to identify the tekhelet is the Talmud. Statements in the Talmud and the Tosefta (supplement to the Mishna) concerning chilazon were no doubt motivated by the need for permanence, the chilazon being the only known permanent dye source at the time. Talmudic references give specific tests in order to determine if a dye is valid tekhelet. Sages developed these chemical tests to determine if the dye was fit to be used as the tekhelet (see Menachot 43a, Rashi and Rambam). These tests were to ultimately show if the dye was colorfast. Kela-ilan, Indigofera tinctoria, could not pass the test.
Lo ifrad hazutei – If its color is permanent then its valid (Men. 43a). The Tiferet Yisrael (Hakdamah to Seder Mo‘ed, pp. 15b–16a) and others suggest that any dye of the correct blue color and colorfastness can be used. Rabbi Yisroel Lipschutz, author of the Tiferet Yisroel commentary on the Mishnah, writes in Kupat HaRochlim that any blue dye that is able to pass the chemical tests outlined in the Talmud may be used.
Kela-ilan could not past the tests.
Woad passes with flying colors!!!
Aimson writing about woad, says, “Its blue dye is more permanent than indigofera indigo.”  
In the Cambridge University Press McNeil describes the process of making woad dye and says, “The dye then gave a strong and permanent blue.” 
Dr. Uhlman writes, “But woad was especially important because, in addition to color, its particular chemistry fixed other more “fugitive” dyes (like orchil and brazil- wood) and made them permanent.” 
It is recorded that woad “was so superior that woad-dyed fabric became part of sumptuary laws and was reserved for royalty.” 
Woad clearly passes all Talmudic requirements as a steadfast dye.
Which Blues Should We Choose?
The Talmud tells us that Kela-ilan is identical in color to the original tekhelet.
Research has shown that the dye from the Murex snail is identical in both color and chemistry as Kela-ilan (indigofera tinctoria).
Research has also shown that WOAD is identical in color and chemistry to both the Murex snail and Kela-ilan!
Let me repeat for emphasis — the dyes from the Murex snail, Kela-ilan, and woad are identical in both chemistry and in color!!!
Huxtable writes that “the dye obtained from both woad (Isatis tinctoria) and indigo (Indigofera tinctoria) is chemically identical” and that “the blue of the tekhelet is chemically identical to the blue of woad and indigo.”  
In his Ancient Egyptian Materials and Industries, A. Lucas writes, “The coloring matter [of woad and Indigofera tinctoria] of which, if not absolutely identical, is so much alike that it is difficult, if not impossible, to distinguish between them.” 
The Woad Less Traveled
In Rambam’s commentary on the Mishna, at the beginning of the chapter Hatechelet (in tractate Menachot) he says, “We are not in possession of it (ie. the Tekhelet) presently, because we do not know how to dye it since not all blue dyes usable for wool are called by the proper name ‘Tekhelet’ only the specific ‘Tekhelet’, we therefore can not dye it at this time, and thus we use only the white (strings for Tzitzit).” This same sentiment is repeated in Responsum 46, that now we use only the white (strings).
In Hilchos Tzittzit 2:1 Rambam makes a statement that clearly is not to be equated with the prohibition and the curse of using kela-ilan, but does express his prejudice against using non-colorfast dyes. He says, “The term techelet when used regarding tzitzit refers to a specific dye that remains beautiful without changing.” He continues to say that if the techelet is not dyed with this dye, it is not fit to be used as tzitzit “even though it is sky blue in color.” Why would the dye not be fit? It would not be fit if it does not remain beautiful without changing. In other words—it must be colorfast. He gives examples such as black dyes, dark dyes and even isatis (In Rambams time they often incorrectly referred to Indigofera Tinctora as isatis. Most probably they confused two different plants, Indigofera Tinctora and Isatis lusitanica which both produced the same dye–indigo). However, it would not be these dyes that were not fit but the way these dyes were being processed which rendered them as impermanent, non-colorfast dyes. As we have seen, woad properly processed will absolutely be a dye that “remains beautiful without changing.” Even more so than mollusk dyes!
In Halacha three he says, “Even though it was purchased from a recognized dealer, if it was checked, and it was discovered that it was dyed with another dark dye which is not of a permanent nature, it is not acceptable.” A footnote to this statement informs us, “The Rambam’s statements appear to imply that the blood of the chilazon must be used for tzitzit, not because of a Torah decree, but because it was the only lasting dye they had.” (Kinat Eliyahu).
It is very plain to see that somewhere in time the correct procedure for processing woad became lost!
Rabbi Dr. Ari Zivotofsky informs us that although both isatis (woad) and kela-ilan both denote indigo and are both the same color as the tekhelet “the terms are not interchangeable.” He continues to say, “Isatis referred to the woad plant, (Isatis tinctoria) . . . while Kela-ilan corresponded to Indigofera tinctoria.”
Many other authorities inform us that Indigofera was clearly Kela-ilan. Woad was not.
Kela-ilan may have indeed dethroned woad for a period of time but it could not erase its place in ancient history nor hinder it’s resurgence to its rightful place in the twenty first century.
A passage in the Mishnah states that the priest is not to raise his hands to pray while his hands were stained with woad because the attention of the people would be on his hands (Mishnah, Megillah 4:7) indicating that in some place and time the priests did indeed dye with woad.
By the Sea
Woad’s blades are a bluish green color of the sea, the form of the leaves are that of an oblong. The Hebrews would have allowed its harvest to rest and regrow every 7 years and again every 70 years. Its resin is used for tekhelet; And in some places and times it was an expensive dye.
Its habitat is mostly the sandy or gravelly sea shores and kelp banks (although it can also be found in desert zones such as Sinai). Woad can be found on the shores of the Mediterranean Sea and it has been suggested that woad is native to the coastal steppe around the Black Sea.
Megillah 6a tells us that the source for tekhelet, referred to here as chilazon, can be found on the shores of the Mediterranean Sea.
The Woad to Discovery
When Roman legions invaded Britain in 55 BC they were allegedly confronted with warriors painted with blue dye from woad. Actors in the movie “Braveheart” recreated the woad painted warriors of old. It is now believed that the healing powers of woad expedited the healing of wounds in the ancient warriors following battle. The renowned herbalist Culpepper praised the healing properties of woad.
Now modern science is discovering many other healthful uses for woad, including the fight against cancer.
The following article appeared in the BBC News:
“ War paint plant ‘tackles cancer.’
A plant Celts used to get blue dye for their war paint is a rich source of a compound that fights breast cancer, scientists have found. Woad, which belongs to the same plant family as cauliflower and broccoli, contains high levels of the compound glucobrassicin.
The Italian team at Bologna University discovered woad contains 20 times more glucobrassicin than broccoli.
They were also able to boost its concentration by damaging the plant.
When the leaves are damaged, glucobrassicin is released by the plant as a defence mechanism. Its derivatives can kill some plant pests. Notably, they also have anti-tumour properties and are particularly effective against breast cancer.”  
The tapestries in the Tabernacle and the covering over the Ark of the Covenant were dyed in tekhelet. We have just learned that woad has substances that can kill pests. Perhaps there was something in woad which assisted in the preservation of the tapestries and articles they covered in the Tabernacle.
The marvels of woad are just now being discovered by science.
Woad is so sufficient in creating dye that woad was initially the choice ingredient used in processing the dye from the Murex snail.
It was once believed that it was gathered from the rocks on the sea shore because when burned it had the scent of the sea.
Dyeing for the Truth
We have discovered some very valuable information about woad thus far.
We have discovered that woad was used in ancient Egypt, from which the Israelites had been delivered, and that traces of woad has been found on ancient Egyptian mummies.
Woad was discovered as the dye which was used on tassels discovered at the archeological dig in Qumran.
Megillah 6a states that it can be found on the shores of the Mediterranean Sea and woad grows by the shores of the sea.
Woad was the first ingredient of choice for initiating the process of making tekhelet dye from the Murex snail.
Woad is not the Kela-ilan which the Talmud prohibits.
Woad produces a dye that is identical to that of Kela-ilan and the Murex snail.
Woad is a superior, permanent, colorfast dye that can pass all the tests outlined in the Talmud with “flying colors!”
The True Blue
The search for the authentic tekhelet seems to be over.
We have discovered it.
It is indigotin, the chemical dye discovered in the Murex snail, Indigofera tinctoria, and woad.
The Murex snail, Indigofera tinctoria, and woad all have in common that they only produce the PRECURSER to the dye called indigotin. Regardless of which source is used the end product is the same—indigotin.
Whether or not you agree that woad was the original source of tekhelet, woad still passes all requirements for authentic uses for tekhelet. There is no disputing that woad produces the very same chemical tekhelet as Murex or Indigofera.
Woad is from a kosher source.
Woad passes all Talmudic tests for being a steadfast dye.
Woad produces pure tekhelet.
Woad (Isatis tinctoria) was most likely the source for tekhelet during the time of Moses. The memory of this source was lost after the Babylonian captivity. With the vast import of dyes from India, woad eventually became replaced by Indigofera tinctoria.
Because of the impermanent nature of Indigofera dye, as well as its unclean manufacturing method, the early rabbi’s began searching for a purer, more permanent dye. This need was met by the Murex snail (or the cuttlefish according to others) which was the only dye they were aware of which was lasting.
Sometime after the destruction of the second Temple the identity of the chilazon became lost. After having lost the identity of the source for tekhelet for a second time in history, rabbinical authority stated one should wear no tekhelet at all until such a time when the source was rediscovered.
Today we have rediscovered the true tekhelet.
The true tekhelet was and still is indigotin.
During the first Temple period the source for indigotin was most probably woad. During the second Temple period the source for indogotin was most probably the Murex snail (chilizon).
The tekhelet must be a colorfast blue dye that remains beautiful without changing.
There is one ancient substance that can produce the pure biblical blue, from a kosher source, while at the same time being able to pass the Talmudic test of being a permanent, colorfast dye. It has the identical color and composition of Murex and Kela-ilan. It was the substance that initially excited the P’til Tekhelet foundation as being part of the Murex dye extraction. It was a substance used in ancient Egypt as well as in ancient Israel — it is the ancient woad.
Woad, more than any other source, has the potential to produce a non-controversial blue dye as well as returning to the world the very ancient and pure biblical techelet.
By Dr. Curtis Ward
- ^ Shabbos 28a
- ^ Kitrossky, Levi, Do We Know Tekhelet?
- ^ http://www.tekhelet.com/kitrossky/tekhelet.htm
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- ^ A. Lucas, Ancient Egyptian Materials and Industries
- ^ White Wool, the Growth of the Ancient Dye Industry and an Expanding Colour Vocabulary, GJ Smith, IJ Miller, V Daniels, A. Smith. Journal of the Society of Dyers and Colourists Volume 113, Issue 4, pages 124–126, April 1997
- ^ Ziderman, I.Irving, The Biblical Dye Tekhelet and its Use in Jewish Textiles
- ^ Roberts, Teresinha, History of Woad
- ^ Aimson, Kate, Using Natural Plant Dyes, Published Beltane 1999
- ^ http://www.whitedragon.org.uk/articles/dyes.htm
- ^ McNeil, NB, Colour and Colour Terminology – Journal of Linguistics, 1972 – Cambridge Univ Press
- ^ Lamdin, Laura C., Chaucer’s Pilgrims: An historical guide to the pilgrims in The Canterbury tales
- ^ http://ancientstandard.com/2010/12/27/woad-not-just-for-warriors-anymore/
- ^ Huxtable, Ryan J., The Mutability of Blue
- ^ http://molinterv.aspetjournals.org/content/1/3/141.full
- ^ A. Lucas, Ancient Egyptian Materials and Industries
- ^ BBC News, Sunday, 13 August 2006, 23:00 GMT 00:00 UK
- ^ http://news.bbc.co.uk/2/hi/health/4783831.stm