The Mystery of the Blue Thread: Rediscovering Tekhelet

In the Torah, the transportation of the Mishkan's vessels is described. While in transit, these vessels were covered to preserve their sanctity. Some were specifically covered with a "tekhelet cover." Tekhelet was used in priestly garments and had various applications in the Mishkan. However, according to Jewish law, it has one principal use meant to persist even today: the tzitzit. The Torah explicitly commands us to include a thread of tekhelet in the tzitzit. Yet, for many years, only white threads adorned the tzitzit. Why is that so?

The Midrash explains that the tekhelet was hidden, and indeed, the method of producing tekhelet from the wondrous snail, as mentioned in the Talmud, remained unknown. This snail is described as having a body the color of the sea, resembling a fish, surfacing once every seventy years, and providing a precious dye from its blood. Despite additional descriptions and knowledge of it in the Talmud, the quest to find it has been long unfulfilled, although in the time of the Amoraim, it was reportedly still in use.

Over a century ago, the Radzyner Rebbe, Rabbi Yitzchak HaCohen Leiner, an illustrious scholar and visionary, embarked on a journey to rediscover the tekhelet. During his search, he traveled to various parts of the world, consulted with experts, and conducted numerous experiments. Ultimately, he concluded that the tekhelet snail was the "common cuttlefish," known for releasing an ink-like cloud for camouflage. He believed the dye used medicinally, associated with its name, also included the component our ancestors used for tekhelet.

He documented his findings in a book that sparked extensive discussion and debate. However, the majority of rabbis did not accept his conclusion, and some claimed that the blue dye produced was not derived from the cuttlefish but rather through a chemical process during dyeing.

In recent decades, a more widely accepted proposal has emerged to identify the Biblical tekhelet snail as the "Murex trunculus," used in ancient times to produce purple dye. Archaeological evidence reveals a significant industry related to this snail, leading some to suggest it might also have been the source of tekhelet.

This identification remains controversial, and most authorities have not embraced it. Nonetheless, several esteemed scholars have accepted it, and they wear tzitzit with threads dyed from the Murex. Perhaps this issue, too, will await the arrival of Elijah the Prophet to resolve our doubts and questions.