Man Lā Yaḥḍuruh al-Faqīh
Hadith 3221893 - وَ رَوَى اَلْحَلَبِيُّ عَنْ أَبِي عَبْدِ اَللَّهِ عَلَيْهِ اَلسَّلاَمُ : أَنَّهُ سُئِلَ عَنْ رَجُلٍ نَسِيَ فَأَكَلَ وَ شَرِبَ ثُمَّ ذَكَرَ قَالَ «لاَ يُفْطِرُ إِنَّمَا هُوَ شَيْءٌ رَزَقَهُ اَللَّهُ فَلْيُتِمَّ صَوْمَهُ».
Hadith.1893 - Al-Halabi narrated from Abu Abdullah (as) that he was asked about a man who forgot and ate or drank, then remembered.
Imam (as) said: "His fast is not broken; it is something that Allah (swt) has provided for him. Let him complete his fast."