The promise he took out for people he might wrong
He began by saying what he is.
اللَّهُمَّ إِنِّي أَتَّخِذُ عِنْدَكَ عَهْدًا لَنْ تُخْلِفَنِيهِ فَإِنَّمَا أَنَا بَشَرٌ فَأَىُّ الْمُؤْمِنِينَ آذَيْتُهُ شَتَمْتُهُ لَعَنْتُهُ جَلَدْتُهُ فَاجْعَلْهَا لَهُ صَلاَةً وَزَكَاةً وَقُرْبَةً تُقَرِّبُهُ بِهَا إِلَيْكَ يَوْمَ الْقِيَامَةِ
Allāhumma innī attakhidhu ʿindaka ʿahdan lan tukhlifanīh. Fa-innamā anā bashar. Fa-ayyu-l-muʾminīna ādhaytuhu, shatamtuhu, laʿantuhu, jaladtuhu, fa-jʿalhā lahu ṣalātan wa zakātan wa qurbatan tuqarribuhu bihā ilayka yawma-l-qiyāmah
“O Allah, I take a covenant with You that You will not break with me. I am only a human being. So any believer I have harmed, or insulted, or cursed, or struck, make it for him a prayer and a purification and a nearness that brings him close to You on the Day of Resurrection.”
Where this comes from
He is arranging in advance for the people he might wrong. Not asking to be forgiven for it. Asking that the injury itself be converted into something that works in their favour on the day it would otherwise be counted against him.
The full narration
Abu Huraira reported Allah's Apostle (ﷺ) as saying:O Allah, I make a covenant with Thee against which Thou wouldst never go. I am a human being and thus for a Muslim whom I give any harm or whom I scold or upon whom I invoke curse or whom I beat, make this a source of blessing, purification and nearness to Thee on the Day of Resurrection
Source
Ṣaḥīḥ Muslim · 6619
- Agreed upon as authentic (al-Bukhārī / Muslim)