The second option is to the advantage of the first wife...
The second option is to the advantage of the first wife because she does not become destitute and alone in her illness. Nevertheless, it must be stressed that in light of the fact that the most important benefit of marriage is familial love, tranquility, and affection, monogamy is far preferable to polygamy. Moreover, Islam does not encourage men to remarry to appease their concupiscence and to sacrifice familial love and peace for evanescent pleasure.
The reason that Islam acquiesces to polygamy is due to a social necessity and in order to protect the rights of widowed women and women who need to marry. Conditions of time, place, societies, and personal resources and facilities differ regarding this issue. If there is no personal or social necessity for polygamy, monogamy is preferable and if polygamy is required in a society or for some persons, women and men must cooperate in attaining this goal.
A man who intends to remarry for one of these reasons must adhere to his financial and physical means and in the event that he does not have the means to manage two households, he must forego remarriage. Then, if he has the means, he must discuss the issue with his wife and prove to her the necessity for remarriage, assure her that he will observe justice and equality among his wives, and obtain her consent in any fair manner possible.
The duty of such a wife is self-sacrifice in order to ensure personal and social necessities; she must set aside harsh emotions, mind the predicament and needs of her husband or widowed women, and above all else, she must think of God’s satisfaction and thus, allow her husband, his legitimate request. If remarriage results through mutual consent of husband and wife, it will be far less problematic for everyone involved.
Conditions for Polygamy Islam tolerates polygamy; however, it has placed various conditions for it that, in practice, are very difficult to observe.