Martin Lings, Muhammad: His Life Based on the Earliest Sources (London, 1983), pp. 247–55; Tor Andrae, Muhammad: The Man and His Faith, trans. Theophil Menzil (London, 1936), pp. 213–15; Watt, Muhammad at Medina, pp. 46–59; Bamyeh, Social Origins of Islam, pp. 222–27
