In Babylonian Talmud Yevamot 63b, we find the following allowance for polygyny if one has an “evil wife” but cannot afford to divorce them:
(VIII) Rabba said, “It is a miṣvah
to divorce an evil wife, as it is written ‘Expel the scoffer and contention departs,
quarrel and contumely cease’ [Prov. 22:10].” Rabba said, “in the case of an
evil wife who has a large ketubba [i.e., marriage settlement] he should
marry another [in addition], as they say, ‘With a rival and not with thorns
[should one deal with his wife].’”
Rabba said, “A bad wife is as difficult as a story day, as it is said, ‘An
endless dripping on a rainy day and a contentious wife are alike’ [Prov.
27:15].”
Rabba said, “Come and see how good is a good wife and how bad is a bad wife.
How good is a good wife? As it is written, ‘He who finds a wife has found
happiness . . .’ If Scripture is referring to the woman, how good is a good
woman that Scripture praises her! If Scripture is referring the Torah, how good
is a good woman that Torah is compared to her! How evil is an evil wife? As it
is written, ‘Now I find woman more bitter than death . . . ‘ If Scripture is
referring to the woman, how evil is an evil woman that Scripture derides her!
If Scripture is referring to Gehenna [i.e., Hell], how evil is an evil woman
that Gehenna is compared to her!”
. . . Rabba advises divorce of an
evil wife. But what if a man cannot afford to divorce his wife? Then he should
marry another, Rabba says, apparently in order to scare her into proper
behavior. (Michael L. Satlow, Jewish Marriage in Antiquity [Princeton:
Princeton University Press, 2001], 9-10)