Musnad Ahmad 649:1

'Abd al-Razzaq narrated to us, Sufyan informed us, from Jabir, from al-Sha'bi, from 'Abd Allah ibn Thabit, who said: 'Umar ibn al-Khattab came to the Prophet, may Allah bless him and grant him peace, and said: "O Messenger of Allah, I passed by a brother of mine from Qurayza, and he wrote for me some comprehensive passages from the Torah. Shall I present them to you?" He said: The face of the Messenger of Allah, may Allah bless him and grant him peace, changed. 'Abd Allah—meaning Ibn Thabit—said: I said to him, "Do you not see what is on the face of the Messenger of Allah, may Allah bless him and grant him peace?" 'Umar said: "We are pleased with Allah the Exalted as Lord, with Islam as a religion, and with Muhammad, may Allah bless him and grant him peace, as a Messenger." He said: Then the state of the Prophet, may Allah bless him and grant him peace, was relieved, and he said: "By the One in Whose hand is the soul of Muhammad, if Moses were to appear among you, then you followed him and abandoned me, you would surely go astray. You are my share among the nations, and I am your share among the prophets."