The Bible identifies the Tzitzith commandment as symbolizing exodus from Egypt. Rashi explains the symbolism of the requirement of a sky blue thread. According to Rashi the sky-blue thread was dark sky blue like the color of the sky just before night. Hence the sky-blue thread symbolizes darkness and night. Night was in fact the time that the first born were smitten and we left Egypt. This has symbolic significance. Throughout the ages when Jews are oppressed with an Egyptian-like tyrany it may be necessary for God as he takes us out of Egypt to kill people quietly at night to save us. In fact throughout the ages Jews have seen such miracles.

There is a controversy between Rashi and Rambam on whether the sky-blue thread in the Tzitzith resembles the color of the sky at night fall or at midday. We have just explained Rashi's approach. But the Rambam believes that the sky-blue resembles the midday sky. Here too we can apply symbolic methods. Daytime is when God drowned the Egyptian army on the Red sea. This has symbolic significaance. Throughout the ages when Jews are oppressed with an Egyptian-like tyrany it may be necessary for God as he takes us out of Egypt to, in broad daylight, kill people who pursue us while we are helpless.In fact throughout the ages Jews have seen such miracles.