Is it permissible for a father to gift his adult children apartments for marriage, similar to how he provides for his daughters, and should the cost of the apartment for the son be equal to the cost of preparing the daughter for marriage, and should he set aside a portion for his younger children for marriage, just as he helped the older ones, and is it permissible to show preference among children with their mutual consent?

The fatwa we adopt is the obligation to treat all children equally, male and female, in gifts and endowments, unless there is a need that necessitates preferring some over others. What a father spends on marrying off his daughters in a customary manner falls under expenses, not gifts, and he is not obligated to give his male children the same amount he spent on his daughters, nor to forgo the share of younger children in exchange for marrying off older ones. Rather, he should give to whoever needs marriage according to their need. He is not permitted to transfer ownership of apartments to them for marriage; merely enabling them to benefit from housing is sufficient.

However, if the dowry for daughters exceeds the amount of need, then the excess is a gift in which equality is obligatory. It is permissible for a parent to favor some children with a gift if the adult, mature children agree to it, as long as their permission remains valid; this is because the reason for prohibition, which is instilling animosity, is absent. As for minor children, their consent to being favored over is not valid because they are not mature.