Is proof not officially registered with the competent authorities, such as the court or the notary public, considered valid in the event of a document attested by witnesses regarding a property endowment or an acknowledgment of property ownership to another, after the death of the property owner?

A gift, Islamically, is validated by the testimony of two acceptable witnesses. It is completed if the donor was competent to dispose of property at the time of the gift, and if the gift was fully possessed by the donee before the donor's death or bankruptcy. Registering the gift in court is not a condition for its validity or completion Islamically. If the gift was not possessed before the donor's death or bankruptcy, it reverts to its owner and is considered an inheritance, unless it was made during a death-illness, in which case it is effective from one-third of the estate for a non-heir. Acknowledging ownership with the testimony of two witnesses is sufficient to prove the acknowledgment, but it does not establish ownership for the acknowledged party unless the acknowledged property genuinely belonged to the acknowledged party.