Fiqh-us-Sunnah Volume 4, Funerals and Dhikr, Fiqh 4.124A.

Anas reported that the Prophet, peace be upon him, said, “When one of you leaves the house he should say, ‘In the name of Allah, I put my trust in Allah. There is no power or strength except with Allah.’ To him is said, ‘This is sufficient for you. You are protected, saved, and guided.’ The devil leaves him alone, saying to another devil, ‘How can you tackle a man who is guided, saved, and well protected.’ (Abu Daw’ud)

A sound hadith reports the following supplication from Anas: “In the name of Allah, I believe in Allah, and I seek protection of Allah. There is no power or strength except with Allah.” (Musnad Ahmad)

Umm Salmah reported that whenever the Prophet, peace be upon him, whenever left her apartment he would look up and then pray, “O Allah, I seek Your refuge against going astray or leading others astray, slipping or causing others to slip, doing wrong or being wronged by others, and behaving arrogantly or being treated arrogantly by others.” (Reported by Tirmizhi, who considers it a sound hadith)