Do the brothers and sisters and their mother have the right to claim shares in a house that was registered in the name of the eldest son, whose lease contract was in his name, especially given that there was an oral will from the deceased father stating that the house is for all his children, and its value was paid from family money, and the eldest son refuses to acknowledge the rights of his siblings?

If the state granted a housing benefit to the father, and then the ownership of the house was transferred to his eldest son for a symbolic price, then the house belongs to him. If the siblings paid money on the basis of partnership, and this did not violate the state's condition, then they are partners to the extent of what they paid. The eldest son's promise to his father is a pledge, and fulfilling it is among the noble virtues, but its religious obligation is a matter of scholarly disagreement. The preponderant opinion is that a promise is religiously binding unless there is an excuse, and legally binding if it is contingent upon a cause and the promisee incurred a cost as a result of the promise. In this case, either fulfillment or compensation for damages is required.

However, if the will pertains to property not owned by the testator, or if it is a will for an heir contingent upon death, it is not permissible unless with the permission of the other heirs. If it is not contingent upon death and is considered a gift, then it is a condition that the donee takes possession before the death of the donor.