Musannaf Ibn Abi Shayba 28:1097

Yahya ibn Sa'id al-Qattan narrated to us, from Ibn 'Ajlan, who said: 'Awn ibn 'Abd Allah narrated to me: That a man came to Ibn Mas'ud and said: "I intend to travel, so advise me." He said: "When you set out, say: 'In the name of Allah, Allah is sufficient for me, I have placed my trust in Allah.' For when you say 'In the name of Allah,' the angel says: 'You have been guided.' And when you say 'Allah is sufficient for me,' the angel says: 'You have been protected.' And when you say 'I have placed my trust in Allah,' the angel says: 'You have been sufficed.'"