What is the ruling when a property is divided among three owners (Zayd half, Amr one-third, Bakr one-sixth), Bakr purchases Zayd's one-third share, then Amr claims preemption on the one-third sale, and then Amr later purchases Bakr's one-sixth share without knowledge of the first purchase, and subsequently learns of the first purchase?

Primary text

Amr has the right to claim his entitlement from the preemption of the one-third sale, which constitutes two-thirds of that share. He takes two-thirds of that portion from Bakr. The remaining one-third of that preemption right is already in Amr's possession due to his separate purchase of the one-sixth share, which he can claim via the preemption of the first sale, thus voiding that part of his own purchase. The remaining portion of Bakr's sold one-sixth share is divided proportionally as preemption rights between Amr and Zayd.