one of the secretaries of Muhammad, and who is one of those who kept a codex of the Qur'an before it was standardized during Uthman's reign as Caliph. Ubayy's codex was destroyed when the Qur'an was standardized. Among the variants with the Uthmanic codex is sura as-Saff 61:6, which reads: "O children of Israel, I am God's messenger to you, and I announce to you a prophet whose community will be the last community and by which God will put the seal on the prophets and messengers." where "Ahmad" is not mentioned, unlike the Uthmanic codex. Another is the mention of muta`, temporary marriage, which some Shiites believe 'Uthman expounged from the Qur'an.