Mukhtasar Muslim

It is narrated from Sayyiduna Abu Bakr Siddiq (may Allah be pleased with him) that he said to the Messenger of Allah (peace and blessings of Allah be upon him): O Messenger of Allah! Teach me a supplication which I may recite in my prayer. The Messenger of Allah (peace and blessings of Allah be upon him) said: Say, "O Allah! I have greatly wronged myself, or committed much injustice against myself, and none forgives sins except You. So forgive me with forgiveness from Your presence, and have mercy on me. Surely, You are the Most Forgiving, Most Merciful."