What is the ruling regarding a mother's revocation of a gift made to her child when the father is deceased?

Primary text

Malik's view states that the mother may revoke a gift made to her child only while the father is alive. If the father is deceased, the revocation is not permitted because the gift is then considered a gift to an orphan, and gifts to orphans are binding, analogous to voluntary charity, in which revocation is not permissible according to his school of thought.