Anas (May Allah be pleased with him) reported:
Messenger of Allah (ﷺ) said, "Whoever says (upon leaving his house): 'Bismillah, tawakkaltu 'alallah, wa la hawla wa la quwwata illa billah [I begin with the Name of Allah; I trust in Allah; there is no altering of conditions but by the Power of Allah],' it will be said to him: 'You are guided, defended and protected.' The devil will go far away from him".
[Abu Dawud, At-Tirmidhi and An- Nasa'i. At-Tirmidhi classified it as Hadith Hasan].
Abu Dawud reported it with this addition: "One devil will say to another: 'How can you deal with a man who has been guided, defended and protected?".
Reference : Riyad as-Salihin 83
In-book reference : Introducti...