Is it permissible for a man to write over his share of inheritance to his wife and daughters while he is still alive, for fear that his family will expel them after his death?

If the intention is to write a will for the wife and daughters, it is not permissible due to the Prophet's (peace be upon him) saying: "Indeed, Allah has given every rightful person his due right, so there is no will for an heir." If he makes a will for them, it is not enforceable unless the rest of the heirs agree.

As for a gift (Hiba): if it is given during a fearful death illness, it takes the ruling of a will. However, if it is given while he is in good health, it is permissible for a mature and discerning person to gift whatever he wishes to his wife and daughters while in good health. It becomes binding if they acquire it and dispose of it as owners. Nevertheless, this should not be done with the intention of depriving brothers of inheritance.