the Babylonian Talmud (Shabbat 156a) refers to Saturn as Shabbetai, i.e., the star of Shabbat (Saturday). Greek and Arab astrology, however, considered Saturn to be the most malignant of the seven planets; and thus the Jews, astrologically governed by Saturn, were considered to be contaminated by the planet’s wicked nature.

https://katz.sas.upenn.edu/resources/blog/saturn-and-jews