Is a father's gift to his two daughters and his wife considered effective, given that he passed away before writing up its contracts, and that he had gifted his male children apartments during his lifetime?

We advise the children to return what their father favored them with, such as apartments and cars, to the estate, because justice in giving gifts among children is obligatory. If the father dies before [achieving] justice, the gift becomes established for those who were favored, according to the majority of scholars. However, some scholars hold the view that the gift is void and must be returned even after the father's death.