Is it permissible to divide the proceeds from the sale of a land, sold with valid and registered contracts before the mother's death, even though its price has not been paid, and what follows from that are questions about the fairness of distribution among the legal heirs, and is there any injustice in this to any of the sons, grandsons, or the wife?

Inheritance matters are complex and require presentation to Sharia courts or consultation with scholars. If a mother registered a portion of her property in the names of some of her children through a fictitious sale, this constitutes a valid gift (hiba) if ownership was transferred to them during her lifetime and they disposed of it. However, a mother is not permitted to favor some children over others in gift-giving, as the Prophet, peace and blessings be upon him, said: "Treat your children equally in giving." Nevertheless, a gift becomes binding upon the death of the giver if it was not revoked beforehand.

Accordingly, each of the brothers owns what the mother specifically designated for him, and the rest of the heirs do not share in it. It is an act of filial piety towards the mother after her death for the children to return those gifts and divide them justly, so that the two sisters receive their share.

However, if the registration was merely a will, it is not enforceable unless the heirs consent to it; otherwise, all of the mother's properties are to be divided according to the Islamic law of inheritance, and any child who died before the mother does not inherit.

If the gift was immediate and the son to whom it was given took possession of it, then he owns it, and it will be inherited from him. But if it was a will, then they (the sons) have no claim to what was registered in their names.