What is the ruling on a man furnishing an apartment for his wife, with whom he has not been blessed with children, for her to benefit from after his death, on the condition that it devolves to his heirs after her death, while her heirs retain their original share of her husband's inheritance?

"Al-Umra" (a lifetime gift) is permissible and legitimate. It is the gifting of usufruct for the duration of the life of the giver or the recipient. If the recipient dies, it reverts to the giver. However, if the gift is not effective until after death, then it is a bequest (wasiyya), and it is not valid for an heir unless the other heirs permit it, or if the wife is divorced and does not inherit, and the house is within the limit of one-third (of the estate), or if the heirs permit it if it exceeds that.