Although it may come as a surprise to many of today’s Jews, the symbols of the zodiac were a common motif of synagogue art in ancient times, and astrology plays an important role in the Talmud, in kabbalistic texts, and even in the works of rationalist rabbis like the medieval poet and Bible-commentator Abraham Ibn Ezra. Unlike the Gregorian calendar, the Jewish calendar combines both lunar and solar elements, so that each month corresponds to a zodiac symbol. The artist Mark Podwal explains the significance of Cancer, which is the constellation for the current month of Tammuz and the subject of a mosaic he designed:
Though the crab is weak, its pinch is excruciatingly painful. The crab’s pinch characterizes the pain the Jewish people endured in Tammuz, [the only] month with no festivals yet a fast day. Legend says that the first of Tammuz was the day that Adam and Eve were expelled from the Garden of Eden.
A midrash adds that the first of Tammuz was the day that Moses—whom God instructed to speak to a rock in order for it to yield water to quench the thirst of the Israelites—sinned by striking the stone instead. As a punishment for not speaking to the rock, God forbade Moses from entering the Promised Land.
You can see an image of the mosaic at the link below.
More about: Astrology, Jewish art, Jewish calendar, Judaism