Sahih al-Bukhari, Book 59, Hadith 5 (In-Book) ⓘ
Narrated Abu Huraira: Allah's Messenger said, "When Allah completed the creation, He wrote in His Book which is with Him on His Throne, "My Mercy overpowers My Anger."
حَدَّثَنَا قُتَيْبَةُ بْنُ سَعِيدٍ، حَدَّثَنَا مُغِيرَةُ بْنُ عَبْدِ الرَّحْمَنِ الْقُرَشِيُّ، عَنْ أَبِي الزِّنَادِ، عَنِ الأَعْرَجِ، عَنْ أَبِي هُرَيْرَةَ ـ رضى الله عنه ـ قَالَ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم " لَمَّا قَضَى اللَّهُ الْخَلْقَ كَتَبَ فِي كِتَابِهِ، فَهْوَ عِنْدَهُ فَوْقَ الْعَرْشِ إِنَّ رَحْمَتِي غَلَبَتْ غَضَبِي " .
also referenced under: Hadith 3194 (DarusSalam) & Volume 4, Book 54, Hadith 416 (USC-MSA)