Following the quote from Avraham that appeared on yesterday’s daf, Rava on today’s daf suggests another set of mitzvot whose source was a statement made by Avraham. Rava teaches that in the merit of Avraham saying “I will not take a thread nor a shoe-strap” (see Bereishit 14:23), his descendants were worthy to receive two commandments – the thread of tekhelet (of tzitzit), and the strap of the tefillin.
Why is tekhelet specified from all the other colors for this mitzva? Because tekhelet is similar to the color of the sea, and the sea is similar to the sky, and the sky is similar to the color of a sapphire, and a sapphire is similar to the Throne of Glory, as it is said, ‘And there was under his feet the like of a paved work of sapphire stone’ (Shemot 24:10), and it is also written, ‘The likeness of a throne as the appearance of a sapphire stone’ (Yeḥezkel 1:26).
It is difficult to precisely identify the color of tekhelet, as there is no clear tradition regarding its hue from the Sages, and over the years the words used for the colors themselves took on different meanings. Even the descriptions that we find in Rabbi Meir’s statement are unclear, since the shades of color found in the sea and in the sky change depending on the season and the time of day. Furthermore, there are other places where Rabbinic statements identify tekhelet as the color of grass or leek.
The rishonim offer a number of definitions for tekhelet:
- The Rambam and Rav Se’adya Gaon say that it is the color of the clear sky.
- Rashi suggests that it is a greenish color, perhaps turquoise
- Rabbi Moshe HaDarshan explains that it is the color of the sky approaching evening, which would suggest a purplish hue.
Similar positions are found among the researchers who have gone in different directions in identifying the ḥilazon, which is the source of tekhelet. If we look to the kala ilan, the “counterfeit tekhelet“, as a way of determining the color, it would be indigo, a very dark blue color (see Massekhet Menaḥot daf 40).