Abu Hurairah (RA) reported from Allah's Messenger (ﷺ) that his Lord, the Exalted and Glorious, thus said. A servant committed a sin and he said: O Allah, forgive me my sins, and Allah (the Exalted and Glorious) said: My servant commited a sin and then he came to realise that he has a Lord Who forgives the sins and takes to account (the sinner) for the sin. He then again committed a sin and said: My Lord, forgive me my sin, and Allah, the Exalted and High, said: My servant committed a sin and then came to realise that he has a Lord Who would forgive his sin or would take (him) to account for the sin. He again committed a sin and said: My Lord, forgive me for my sin, and Allah (the Exalted and High) said: My servant has committed a sin and then came to realise that he has a Lord Who forgives the sins or takes (him) to account for sin. O servant, do what you like. I have granted you forgiveness. 'Abdul A'la said: I do not know whether he said thrice or four times to do "what you desire".
Abu Hurairah (RA) reported he heard Allah's Messenger (ﷺ) as saying that a servant committed a sin. The rest of the hadith is the same, but there is a slight variation of wording.
Abu Mu'sa reported Allah's Messenger (ﷺ) as saying that Allah, the Exalted and Glorious, Stretches out His Hand during the night so that the people repent for the fault committed from dawn till dusk and He stretches out His Hand during the day so that the people may repent for the fault committed from dusk to dawn. (He would accept repentance) before the sun rises in the west (before the Day of Resurrection).