Before Moshe’s lone ascent to Mount Sinai for forty days and forty nights, he ascended briefly with Aharon, Nadav, Avihu, and seventy Elders of Israel. Their spiritual episode is recorded as follows:
“And they saw the G-d of Israel: under His feet there was the likeness of a pavement of sapphire, like the very sky for purity. (Exodus 24:10)”
Similarly, Ezekiel describes a complex vision (Ezekiel 1) in which, among other things, he sees a semblance of a throne in appearance like sapphire.
Tekhelet gains its religious significance by virtue of its color association with these sapphire visions. The Talmud (Sotah 17b) quotes Rabbi Meir as saying:
Why particularly Tekhelet [for the mitzvah of tzitzit] from among all other colored materials? Because Tekhelet is similar to the sea, and the sea is similar to the sky, and the sky is similar to the Holy Throne. As it says, “And they saw the G-d of Israel: under His feet there was the likeness of a pavement of sapphire, like the very sky for purity (Exodus 24:10),” and as it is written, “in appearance like sapphire stone was the semblance of a throne (Ezekiel 1:26).”
Rabbi Aryeh Kaplan, in his book Jewish Meditation, regards this passage in the Talmud as a description of a contemplation meditation. With the blue thread as the subject of such a meditation, one can experience the cool calmness of the sea and the serenity of its depths. One’s thoughts are then directed up to the heavens, higher and higher, up to the farthest reaches of the sky. Then one’s thoughts penetrate the sky, and one approaches the Throne of Glory.
