Is the brother's statement, "The three dunums are for the three unmarried sons and the two daughters," considered a will that must be executed, or is this land considered part of the brother's property and distributed as an inheritance according to the laws of inheritance in Islamic Sharia?

The statement that the three dunams for unmarried sons and daughters are considered a gift (hibah): if they took possession of them before the death of the donor, then their ownership is established. Otherwise, the gift becomes void and part of the estate, because a gift is not binding except by taking possession or seizure (qabd or hiyazah). It is considered a will (wasiyah) if he gifted it during his death illness and it is disbursed from one-third of his estate, or if the donor said that it would become their property after his death.