The seal is a rectangular piece of red agate, about 1 cm in length, inscribed with الله / محمد رسول (i.e., Allah "God" in the first line, and Muḥammad rasūl "Muhammad, messenger" in the second). According to Muslim historiographical tradition, Muhammad's original seal was inherited by Abu Bakr, Umar, and Uthman, but lost by Uthman in a well in Medina. Uthman is said to have made a replica of the seal, and this seal was supposedly found in the capture of Baghdad (1534) and brought to Istanbul.[2]