Musnad Abu Ya'la al-Mawsili 106:11

Mujahid ibn Musa narrated to us, Bahz narrated to me, Shu'bah narrated to us, from Abu Ishaq, from al-Rabi' ibn al-Bara', from his father: That the Prophet, peace and blessings of Allah be upon him, when he returned from his journey, would say: "Returning, repenting, worshipping, to our Lord praising."