How are apartments that a father gifted to his sons and daughters during his lifetime to be distributed, given that no official written contract was made, but delivery, usufruct, and disposition by sale occurred for some of them? Are these considered complete gifts, or is the amount the father paid to some of his sons in exchange for buying their shares counted as part of the gift?

If the father has acted justly in the gift and the children have taken possession of it, such that they are able to dispose of it, then the gift is complete. This is based on the hadith of Aisha, may Allah be pleased with her, that Abu Bakr gifted her twenty wasqs of dates. When he fell ill, he said: "Had you harvested them or taken possession of them, it would have been so. But today it is the property of the heirs."

Scholars have differed on the ruling regarding a gift if the donor dies before the donee takes possession. The Shafi'is and Hanbalis hold that it does not become void, and the heirs stand in the place of the donor. In contrast, the Hanafis, Malikis, and some Hanbalis hold that it becomes void.

Regarding the question at hand, it appears that possession has been taken, evidenced by some children residing in the properties and others renting or selling them. As for the children selling the apartments to their father for a lower price, if the sale was by mutual consent, then it is complete and binding. However, if the son was unable to sell to an outsider and accepted the price out of shyness, then he should be given the full price of the apartment from the inheritance to absolve the father's responsibility. But if he could have sold to an outsider, he is not compensated. The best approach is reconciliation and mutual agreement, so that each one who sold is given the remaining portion of his apartment's price at the rate it was worth at the time of sale.