Are the funds that a father allocated for his daughters during his lifetime, whether they were bank certificates in the daughters' names for marriage preparations or a joint sum for purchasing land, considered a valid gift or part of the inheritance, especially since the father passed away before handing them over or distributing them?

Everything that a father endowed to his children but they did not take possession of during his lifetime is part of the inheritance and is to be divided among the heirs. A mere registration certificate is not sufficient for the completion of the endowment (hiba). Rather, the donee must take possession of the endowed item and dispose of it for its ownership to be perfected. Possession is the act of acquiring and having control over the item.