It is narrated from Sayyiduna Abdullah bin Amr (may Allah be pleased with him) that Sayyiduna Abu Bakr Siddiq (may Allah be pleased with him) said to the Messenger of Allah (peace and blessings be upon him): Teach me a supplication so that I may recite it in prayer. The Prophet (peace and blessings be upon him) said: Recite this supplication: "O Allah! Indeed, I have wronged myself greatly, and none forgives sins except You, so forgive me with a forgiveness from Yourself, and have mercy on me. Indeed, You are the Most Forgiving, Most Merciful."

Abu Majliz says: Sayyiduna Ammar bin Yasir (may Allah be pleased with him) led us in a prayer, and he shortened it, so the people objected to this. But he said: Did I not perform the bowing and prostration properly? They replied: Of course. Then he said: In this prayer, I recited a supplication which the Messenger of Allah (peace and blessings be upon him) used to recite. That supplication is:

“O Allah! By Your knowledge of the unseen and Your power over the creation, I ask You (that) as long as You consider life better for me, keep me alive, and when death is better for me, cause me to die. I ask You for Your fear in private and in public, for speaking the word of truth in anger and in pleasure, for moderation in poverty and in wealth, for the delight of looking at Your Face, and for the longing to meet You. And I seek refuge in You from a harmful calamity and from a misleading trial. O Allah! Adorn us with the adornment of faith and make us guides who are rightly guided.”

It is narrated from an Ansari Companion of the Messenger of Allah (may Allah be pleased with him) that he heard the Noble Prophet (peace and blessings be upon him) reciting this supplication in prayer: "O Allah! Forgive me and accept my repentance, indeed You are the Acceptor of repentance, the Most Forgiving." (O Allah! Forgive me and accept my repentance, for You alone are the Acceptor of repentance, the Most Forgiving.) The Prophet (peace and blessings be upon him) recited this supplication one hundred times.

An old woman from Banu Numayr heard from the Noble Prophet (peace and blessings be upon him) while he (peace and blessings be upon him) was leading the people in prayer and his face was towards the House of Allah, and she remembered this supplication from him (peace and blessings be upon him): "Rabbighfir li khatayaya wa jahli." (O my Lord! Forgive my mistakes and my acts of ignorance.)

Sayyiduna Mu’adh bin Jabal (may Allah be pleased with him) says: The Messenger of Allah (peace and blessings be upon him) met me and said: O Mu’adh! Verily, I love you. I replied: O Messenger of Allah! By Allah, I also love you. The Prophet (peace and blessings be upon him) said: I advise you with a few words; you must recite them after every prayer. They are:“O Allah! Help me to remember You, to thank You, and to worship You in the best manner.”