Authentic Supplication Number 54.
The Messenger of Allah said: Whoever says – upon going out of his home: Bismillah, tawakkaltu `ala ‘allah, la hawla wa la quwwata ‘illa bil-lahi ta`ala, it is said to him: You have been sufficed, protected, and guided, and the shaytan would move aside from him, then say to another shaytan: What access do you have to a man that has been guided, sufficed, and protected?”.
Reported by Abu Dawood, An-Nisa’ee , and At-Tirmithi and he said it was comely-sound. Al-Albani said it is as At-Tirmithi said; rather, he said, it is sound, and he said that Ibn Hibban also reported it in his Saheeh. Al-Albani included this hadeeth in The Authentic of Good Sayings as #44.