What is the ruling if a minor (sabi) claims they conducted the sale?
Chapter on Selling the Musarrah (Animal with milk retained in udder)
Al-Mughni
Book of Sales
Primary text
If the seller claims they were a child when entering the contract, the statement of the buyer is accepted. This is the position narrated and attributed to Al-Thawri and Ishaq. This is because both parties agree that a contract occurred, and they only differ on a factor that might void it; therefore, the ruling favors the one asserting validity, similar to the previous case regarding voiding conditions.
Supporting text
An alternative view, held by some Shafi'i scholars, is that the statement of the one claiming minority should be accepted because their minority is the default state. This differs from the cases of void conditions or duress because, in those cases, the default is the absence of such factors, whereas here, the established fact is that the individual was in a state (minority) that needs to be overcome. Furthermore, the presumption is that a responsible adult (mukallaf) only engages in sound transactions, which is not the presumption when minority is claimed.