Aside from the heirs, the recipient of a bequest may be Muslim, non-Muslim, or even an apostate or a ḥarbi (citizen of an enemy state). It was reported that the Prophet’s wife Ṣafiyah bequeathed part of her estate to some of her Jewish relatives. A bequest is also valid for a fetus in the womb.
Not Eligible to Receive Bequests
Someone who is not in existence at the time of the waṣiyah is not eligible; for example, the child a certain woman will bear or future grandchildren who have not yet been conceived. Also, animals are not eligible recipients per (A), although making a waṣiyah for certain animals that benefit humans is valid because the intent here is for the benefit attained by those humans.
Other scholars have been known to allow endowments for the support of aged animals, stray dogs and cats, etc. In his book Civilization of Faith, Shaykh Mustafa as-Siba’ee mentions several examples of endowments set up in Damascus for these types of animals.
Back when the discussion of waṣiyah to slaves was pertinent, it was agreed that they were eligible for tadbeer.