Sahih al-Bukhari 6669

Arabic

حَدَّثَنِي يُوسُفُ بْنُ مُوسَى، حَدَّثَنَا أَبُو أُسَامَةَ، قَالَ حَدَّثَنِي عَوْفٌ، عَنْ خِلاَسٍ، وَمُحَمَّدٍ، عَنْ أَبِي هُرَيْرَةَ ـ رضى الله عنه ـ قَالَ قَالَ النَّبِيُّ صلى الله عليه وسلم ‏ "‏ مَنْ أَكَلَ نَاسِيًا وَهْوَ صَائِمٌ فَلْيُتِمَّ صَوْمَهُ، فَإِنَّمَا أَطْعَمَهُ اللَّهُ وَسَقَاهُ ‏"‏‏.‏

English translation

Narrated Abu Huraira:The Prophet (ﷺ) said, "If somebody eats something forgetfully while he is fasting, then he should complete his fast, for Allah has made him eat and drink

Reference: Sahih al-Bukhari 6669, Book of Oaths and Vows. English translation by Dr. Muhammad Muhsin Khan.