What is the position of Sharia regarding someone who claims a gift by oath without evidence after the death of the donor, and is evidence necessary to prove the gift?

Such matters are not to be ruled upon through a fatwa; rather, they require the judgment of a judge or an arbiter who can hear from both parties, examine the evidence, and settle the dispute. Therefore, a father's permission for some of his children to utilize his house does not imply ownership but rather carries the meaning of a loan until the gift is proven. Even the father's statement, "Honor my son," does not confer ownership upon the son except through attestation. The son is only entitled to the value of his labor, minus depreciation. If some heirs claim a gift from the deceased and the rest deny it, the claimant must provide lawful evidence; otherwise, he has no recourse but to ask the remaining heirs to swear an oath denying knowledge.