Is the condition stipulating the wife's return of her gift to her husband in the event of divorce valid and binding, and is expiation for an oath (kaffarat yameen) due upon her if she fails to fulfill it in the event the condition is void?

The condition associated with a gift is a point of contention among jurists. The majority of jurists hold that the condition is void but the contract is valid, while the Malikis, Shafi'is, and Hanbalis, in one opinion, consider both the contract and the condition void. Among the conditions for the validity of a gift is possession. Therefore, if you did not vacate the house for your wife, the house remains your property. If the gift was completed and your wife took possession of the house, then you are not permitted to revoke it, and your wife is not obligated to return your share of the house to you. However, she is obligated to offer expiation for the oath she swore. Some scholars have allowed for the conditioning of a gift upon a stipulation, and according to this opinion, you would have the right to demand your wife return your share.