Sayyiduna Abdullah bin Mas'ud (may Allah be pleased with him) narrates from the noble Messenger (peace and blessings be upon him) that whenever he delivered a sermon he would say: "All praise is for Allah. We seek His help and His forgiveness, and we seek refuge in Allah from the evils of our souls. Whomever Allah guides, none can lead him astray, and whomever Allah leads astray, none can guide him. I bear witness that there is no god but Allah, and that Muhammad (peace and blessings be upon him) is His servant and Messenger. Allah has sent him before the Hour as a bearer of glad tidings and a warner. Whoever obeys Allah and His Messenger has succeeded, and whoever disobeys will harm only himself and will not harm Allah in the least."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب النكاح / 13830