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 sas 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. 'Abd al-A'la said: I do not know whether he said thrice or four times to do" what you desire". (Using translation from Muslim 2758a)   

عَنِ النَّبِيِّ ﷺ فِيمَا يَحْكِي عَنْ رَبِّهِ تَبَارَكَ وَتَعَالَى قَالَ أَذْنَبَ عَبْدٌ ذَنْبًا فَقَالَ اللهُمَّ اغْفِرْ لِي قَالَ يَقُولُ اللهُ تَبَارَكَ وَتَعَالَى أَذْنَبَ عَبْدِي ذَنْبًا عَلِمَ أَنَّ لَهُ رَبًّا يَغْفِرُ الذُّنُوبَ وَيَأْخُذُ بِالذَّنْبِ ثُمَّ عَادَ فَأَذْنَبَ ذَنْبًا فَقَالَ اللهُمَّ اغْفِرْ لِي قَالَ يَقُولُ تَبَارَكَ وَتَعَالَى أَذْنَبَ عَبْدِي ذَنْبًا عَلِمَ أَنَّ لَهُ رَبًّا يَغْفِرُ الذَّنْبَ وَيَأْخُذُ بِالذَّنْبِ قَالَ ثُمَّ عَادَ فَأَذْنَبَ ذَنْبًا فَقَالَ اللهُمَّ اغْفِرْ لِي فَقَالَ تَبَارَكَ وَتَعَالَى أُرَاهُ قَالَ أَذْنَبَ عَبْدِي ذَنْبًا عَلِمَ أَنَّ لَهُ رَبًّا يَغْفِرُ الذَّنْبَ وَيَأْخُذُ بِالذَّنْبِ اعْمَلْ مَا شِئْتَ فَقَدْ غَفَرْتُ لَكَ