What is the ruling on a father waiving his share of his deceased wife's inheritance to her two sons only (full brothers), to the exclusion of his son from another wife, so that the latter does not inherit from the father's share in the mother's estate if the father dies, while it is permissible for him to inherit from the father's other wealth?

If the heirs of the mother are limited to the husband and the two children, then the husband receives one-fourth due to the presence of a lineal descendant, and the remainder goes to the children by way of ta’sib (agnatic inheritance). The husband’s selling his share to the deceased wife’s two children is permissible, provided it is not an act of favoritism. Giving his share to them without including his other son is contrary to the justice required in giving gifts among children.