"Abu Dawood reported in his Sunan that the Messenger of Allah (S) said: “If a man goes out of his house and says, ‘Bismillaah, tawakkaltu ‘ala Allah, laa hawla wa laa quwwata illaa Billaah (In the name of Allah, I put my trust in Allah, there is no help and no strength except in Allah),’ it will be said to him, ‘This will take care of you, you are guided, you have what you need and you are protected.’ The Shaytaan will stay away from him, and another shaytaan will say to him, ‘What can you do with a man who is guided, provided for and protected?’"
(Reported by Abu Dawood and al-Tirmidhi. Saheeh al-Jaami’, no. 499)
(Source: fallenpeach, via emil-i-am)