Is a grandmother's oral relinquishment of her share of her deceased son's inheritance considered effective, or does her share transfer to her heirs after her death, noting that there were witnesses to the relinquishment and the inheritance has not yet been distributed?

If an adult, sane, and willing heir renounces their share of the inheritance, their renunciation is valid and enforceable and is considered a gift (hibah). A gift, according to the majority of scholars, is not binding unless possession is taken, except if the gifted item is already in the possession of the donee; in such a case, the gift becomes valid merely upon offer and acceptance.

Therefore, the grandmother's renunciation of her share is enforceable if the estate is already in the possession of those to whom she renounced it. However, if the estate is not in their possession, the gift is not enforceable, and her renunciation becomes void upon her death due to the lack of possession, and her share reverts to her heirs. For a gift becomes void upon the death of the donor or the donee before possession is taken.