Musnad Ahmad 27:1914

'Abd al-Razzaq narrated to us, Ibn Jurayj informed us, Abu al-Zubayr informed me, that 'Ali al-Azdi informed him that Ibn 'Umar taught him that when the Messenger of Allah (peace and blessings of Allah be upon him) would settle upon his camel to set out on a journey, he would say "Allahu Akbar" (Allah is the Greatest) three times, then say: "Exalted is He who has subjected this to us, and we could not have [otherwise] subdued it. And indeed we are, to our Lord, about to return." (Az-Zukhruf: 13-14). "O Allah, we ask You in this journey of ours for righteousness and piety, and for deeds that please You. O Allah, make this journey of ours easy for us, and shorten its distance for us. O Allah, You are the Companion in the journey and the Successor regarding the family. O Allah, I seek refuge in You from the hardships of travel, the gloominess of the return, and a bad sight regarding family and wealth." And when he returned, he would say them, and add to them: "Returning, repenting, worshipping, and praising our Lord."