Sayyidah Umm Salamah (may Allah be pleased with her) says that when the Messenger of Allah (peace and blessings be upon him) went out of his house, he would say: 'Bismillah. Allahumma inni a'udhu bika an azilla aw adilla aw azlima aw uzlama aw ajhala aw yujhala alayya' (In the name of Allah. O Allah, I seek refuge in You lest I slip or go astray, or wrong anyone or be wronged, or act ignorantly towards anyone or have anyone act ignorantly towards me.)
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الحج / 10309
Sayyiduna Anas bin Malik (may Allah be pleased with him) says that the Messenger of Allah (peace and blessings be upon him) said: "Whoever says: 'In the name of Allah, I have put my trust in Allah, and there is no power to avoid sin nor strength (to do good) except with the help of Allah,' it is said (to him): 'You have been protected and you have been sufficed.'"
Hajjaj bin Muhammad also narrated it from Ibn Jurayj and added in it: "when he goes out of his house."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الحج / 10310