techeletIn Maseket Berachot the question of when to recite the morning shema hinges on the phrase "when you can tell the blue threads from the white threads." This is a practical halakhic consideration echoing from the Beit HAMikdash that governs being kovea itim. Today poskim ask when should the shema be said in a space ship when the sun rises every hour, or in Scandaneivia when it is dark for extended periods. Techelet is used in the clothing of the High Priest, the tapestries in the Tabernacle, and the tassels ( ציצית ] affixed to the corners of one's four-cornered garment, such as the Tallit (garment worn during prayer, which the Midrash notes Hashem wrapped Himself in to create the world with the Torah blueprint.. This color is biblically based from— Numbers 15:37-39 and discussed in many rabbinic texts such as — Mishnat Rabbi Eliezer, ch. 14. & Midrash, Numbers 17:5 & — Sifre, Shelach, 15:39. The dye of Tekhelet was produced from a marine creature known as the Ḥillazon/Chilazon). According to the Tosefta (Men. 9:6), the Ḥillazon is the exclusive source of the dye. Recently Rabbi Leiner after the 1858 the French zoologist Henri de Lacaze-Duthiers found that three Mediterranean mollusks produced purple-blue dyes [One, Murex trunculus] published two books to counter the strong opposition from other Torah scholars who did not agree with his conclusions .
Esoterically Maseket Hagigah 12b-14b testifies that Rabbi Akiva in the arba sheniknasu biPardes, went up to the 7th heaven and said "al tamru mayim mayim." Josephus gives a clue to uncover a basic peshat level of Rabbi Akiva's cryptic remark. Rabbi Akiva had witnessed the Temple when it stood before the Romans destroyed this most holy place of sanctity and Josephus further notes that when the sun was up the light of the sun would rickochet off the painted blue marble (A Roman artistic and architectural invovation along with hydrolic concrete used to make the harbor in Caesarea) creating the illusion of shimmering beautiful blue waters, like the Mediterreanean sea. This relates to a sugya in Hullin that the blue threads of the tzizit make on think of the Medetareanan pure waters of blue, which make one think of the blue sky (the rakiah= firmament), which make one think of the throne of Hashem (kisei-ha-kavod- also according to the Midrash) this beautiful blue color. Today in Safed Rabbi Aboab's shul that contains a sefer torah from the explusion from Spain in 1492 employs blue paint for mystical reasons to beautify the synagogue. However the attached articles testify to the many intricate halakhic practical questions regarding identifying the true blue color that the priests (Kohanim) employed on the tzitzit garments, indeed when they could distinguish between the blue and white threads. These halakhic articles speak of the "ties that bind" with regard to the importance of Jewish law in a pratical sense in identification of the ancient techelet which the gemarah notes turned purple sometimes in sunlight. Today the Techelet institute has mapped the molecular structure of what some scientists identify as indigo in relation to techelet while others like Rabbi Herzog who wrote his dissertation on this subject identify with the dye produced from a snail in the Mediterranean. The debate goes on and the signficance includes practical halakhic considerations-criteria-analysis as well as cosmic esoteric mystical ramifications, as the Rashbi himself is said in the Bar Yochai mantra to have entered the Kodesh Kodeshim of pure blue stone (avnei shay-yesh). בַּר-יוחַאי, לִמְקום אַבְנֵי שַׁיִשׁ
הִגַּעְתָּ וּפְנֵי אַרְיֵה לַיִשׁ,
גַּם גֻּלַּת כּותֶרֶת עַל עַיִשׁ,
תָּשׁוּר וּמִי יְשׁוּרֶךָ.
