Musannaf Ibn Abi Shayba 21:496

Al-Fadl ibn Dukayn narrated to us, Sa'id ibn 'Abd al-Rahman narrated to us, from Yahya ibn Abi Ishaq, from Anas ibn Malik, that he was with the Messenger of Allah, may Allah bless him and grant him peace. When he was at Zahir al-Bayda' or al-Harrah, the Messenger of Allah, may Allah bless him and grant him peace, said: "Returning, repenting, if Allah wills, to our Lord praising."