Found a good site that addresses the Jewish portion of your question.
Here's a quote from the link (below):
"It was a heritage from the past and it was left undisturbed. As the civilization of the people reached a higher form and, especially under the teaching of the prophets, their moral and religious consciousness developed, the polygamous system gradually declined.
This is noticeable in Israel after the return from the Exile.
In the Second Commonwealth polygamy is far from general (cf. Tobit and Susanna). Yet it survived far into the Christian era. In the New Testament Jesus neither condemns polygamous unions nor advocates a change in the system.
From this noninterference attitude Luther, as late as the 16th cent., arrived at the conclusion that he could not forbid the taking of more than one wife."
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