Sunan al-Shafi'i

It is narrated from Sayyiduna Ali bin Abi Talib (may Allah be pleased with him) that when the Prophet Muhammad (peace and blessings be upon him) would begin the obligatory prayer, he would recite this supplication: "I have turned my face towards Him who created the heavens and the earth, being ever-inclined to the true religion, and I am not among the polytheists. Indeed, my prayer, my sacrifice, my life, and my death are for Allah, the Lord of all the worlds, who has no partner. This is what I have been commanded, and I am of those who submit. O Allah, You are the King, there is no true deity except You. You are pure, and all praise is for You. You are my Lord, and I am Your servant. I have wronged myself, I confess my sins, so forgive all my sins, for none forgives sins except You. Guide me to the best of manners and character, for none guides to the best of them except You. Turn me away from bad manners and habits, for none can turn them away except You. Here I am, obedient to You. All good is in Your hands. The one whom You guide is truly guided. I seek Your help and turn to You. You are blessed and exalted. I seek forgiveness from You and turn to You in repentance."