Ptil Tekhelet (Thread of Blue)
I wrinkled my nose at the briny smell as I moved closer to photograph the clear plastic cup full of greenish liquid. Resting on the bottom of the cup were the dried glands of several chilazon, the Hebrew word most closely identified as the present day mollusk, murex trunculus. As 25 curious students looked on, the guest presenter, Dr. Ari Zivotofsky from Bar Ilan University proceeded to dip a swath of pure white wool into the murky solvent. Lo and behold, the soaked greenish-yellow wool slowly changed to a rich blue color, known in the Hebrew sources as tekhelet, the unique blue dye used to color the tsitsit (ritual fringes) and priestly garments of ancient Israel.
What a privilege it was to learn alongside these young adults who were enrolled in The Object is the Object, Dr. Barry Freundel’s freshman seminar at Towson University. On Thursday, November 10, Dr. Zivotofsky expertly took the students on a journey from biblical to modern times, exploring the early textual references to ptil tekhelet, which are repeated daily in the Sh’ma blessing: “And it [ptil tekhelet] shall be for you as a fringe, that you may look upon it and remember all the commandments of G-d, and do them…” (Numbers 15:38-39).
The symbolism of ptil tekhelet is multifold; the rich blue colors recall the ocean and the infinite sky, reminding us of G-d’s presence in the world and of the bond between the wearer and G-d.
Yet, over time, the wearing of tekhelet became relegated only to royalty, placed under restrictions during Roman times, and ultimately banned after the Arab conquest. Thus, the source of this special dye was lost to modern knowledge, only to be rediscovered following research and exploration in the late 20th century. Citing sources in the Talmud that referred to the special properties of tekhelet, researchers embarked on numerous diving expeditions off the coast of northern Israel that led to the identification of the most likely match for the chilazon. As it turns out, the dye is derived from a relatively rare snail found in the Mediterranean. This murex trunculus shellfish found off the coast of what was once ancient Phoenicia contains a special gland that produces the indigo-colored permanent dye. Today, the ancient dying process used to make tekhelet has been revived and wearers of the blue threads can be seen throughout the Jewish world.