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