Is it permissible for a grandfather to single out one of his grandchildren for a gift from his possessions, to the exclusion of others, after distributing his possessions among his children according to Islamic law?

It is permissible for a person to divide his wealth among his children, provided there is justice, meaning the male receives double the share of the female. However, it is disliked for him to do so if he is still able to have more children. As for the grandfather, he is not obligated to be just among his grandchildren in giving gifts; rather, it is commendable. There is no harm upon him if he singles out some of his grandchildren for gifts over others, provided that this is not a ruse to increase the share of some of his children.