Must a husband give his wife half of the house he promised her and swore an oath upon, in return for her significant financial assistance to him, if she refuses to allow his parents to live in this house, and this has caused problems that may lead to divorce?

The preponderant opinion is that a gift is not binding until it is taken possession of. Thus, it is permissible to revoke it as long as the donee has not taken possession of it, though revocation is disliked. Therefore, you are not obligated to give your wife half of the house you promised her as a reward for her assistance. However, if you affirmed the promise with an oath, you are liable for an expiation for breaking an oath if you do not give it to her. It is not your wife's right to prevent you from housing your parents, but she can oblige you to provide her with separate accommodation. It is advisable for the spouses to communicate and avoid discord and divorce, and to be keen on cohabiting with kindness. It is also advised not to revoke the gift or to compensate the wife financially for her good deed.