Sahih al-Bukhari 6405
Book 80: Invocations · Narrated by Abu Huraira
Arabic
حَدَّثَنَا عَبْدُ اللَّهِ بْنُ مَسْلَمَةَ، عَنْ مَالِكٍ، عَنْ سُمَىٍّ، عَنْ أَبِي صَالِحٍ، عَنْ أَبِي هُرَيْرَةَ ـ رضى الله عنه ـ أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم قَالَ " مَنْ قَالَ سُبْحَانَ اللَّهِ وَبِحَمْدِهِ. فِي يَوْمٍ مِائَةَ مَرَّةٍ حُطَّتْ خَطَايَاهُ، وَإِنْ كَانَتْ مِثْلَ زَبَدِ الْبَحْرِ ".
English translation
Narrated Abu Huraira:Allah's Messenger (ﷺ) said, "Whoever says, 'Subhan Allah wa bihamdihi,' one hundred times a day, will be forgiven all his sins even if they were as much as the foam of the sea
Reference: Sahih al-Bukhari 6405, Book of Invocations. English translation by Dr. Muhammad Muhsin Khan.