When Ibn 'Umar left his house, he used to say, "O Allah, keep me and those with me safe!"  

أَنَّ ابْنَ عُمَرَ كَانَ إِذَا خَرَجَ مِنْ بَيْتِهِ قَالَ اللَّهُمَّ سَلِّمْنِي وَسَلِّمْ مِنِّي  

Abu Hurayra reported that the Prophet, may Allah bless him and grant him peace, used to say when he left his house, "In the Name of Allah. Reliance is on Allah. There is no power nor strength except by Allah."  

عَنِ النَّبِيِّ ﷺ أَنَّهُ كَانَ إِذَا خَرَجَ مِنْ بَيْتِهِ قَالَ بِسْمِ اللهِ التُّكْلاَنُ عَلَى اللهِ لا حَوْلَ وَلا قُوَّةَ إِلا بِاللَّهِ