Abu Dawud
General Behavior
Book Number: 036 / Hadith Number: 5076
Narated By Anas ibn Malik : The Prophet (pbuh) said: When a man goes out of his house and says: "In the name of Allah, I trust in Allah; there is no might and no power but in Allah," the following will be said to him at that time: "You are guided, defended and protected." The devils will go far from him and another devil will say: How can you deal with a man who has been guided, defended and protected?