Astrology, and whether the celestial bodies impact our lives. Namely, depending on which day of the week you were born, your traits and/or success will follow the events of the days of creation. Alternatively, the determining factors in our fates were the hours of the day. And yet, the very strong statement that "ein mazal le-Yisrael" - that astrological sign does not hold sway over Israel. Or perhaps - Israel has the means to overcome the astrology that was otherwise accepted to be governing lives.