Jewish marriage law absorbed the surrounding civilization’s marital norms.

Evidence

It is not my purpose to go into any detail on this, but merely to draw your attention to one or two examples. Even in a matter as intimate and personal as marriage, we see the Jews of the Islamic world adopting procedures regarding marriage roughly in accord with those of the Islamic world. There are differences, notably in the prohibition of concubinage, but the rule of polygamy was maintained. On the other hand, in the Christian world there was the famous takana outlawing polygamy and imposing the Christian-inspired rule of monogamy. — Bernard Lewis, From Babel to Dragomans, 327