Musnad Ahmad 658:186

He said: 'Abd al-Malik ibn 'Amr narrated to us, he said: Sufyan narrated to us, from Abu Ishaq, from al-Bara' ibn 'Azib, that the Prophet, peace and blessings of Allah be upon him, when he would return from a journey, he would say: "Returning, repenting, to our Lord praising."