The doa when leaving home is: 'Bismillah, tawakkaltu 'alallah, wa la hawla wa la quwwata illa billah' — In the name of Allah, I place my trust in Allah, and there is no power nor strength except with Allah. It is said that whoever recites this is guided, sufficed, and protected.
بِسْمِ اللَّهِ، تَوَكَّلْتُ عَلَى اللَّهِ، وَلَا حَوْلَ وَلَا قُوَّةَ إِلَّا بِاللَّهِ
Bismillah, tawakkaltu 'alallah, wa la hawla wa la quwwata illa billah.
Meaning: In the name of Allah, I place my trust in Allah, and there is no power nor strength except with Allah.
Source: Sunan Abu Dawud #5095Nabi (shallallahu alaihi wa sallam) said that when doa ini is recited upon leaving home, the person is told (by the angels): 'You have been guided, you have been sufficed, and you have been protected.' And the devil moves away from him, saying to another devil: 'How can you deal with a man who has been guided, sufficed, and protected?'
بِسْمِ اللَّهِ، تَوَكَّلْتُ عَلَى اللَّهِ، وَلَا حَوْلَ وَلَا قُوَّةَ إِلَّا بِاللَّهِ
The Prophet (peace be upon him) said: 'When a man leaves his house and says: Bismillah, tawakkaltu 'alallah, wa la hawla wa la quwwata illa billah, it is said to him: You have been guided, sufficed, and protected, and the devil moves away from him.'