(18) باب تَفَكُّرِ الرَّجُلِ الشَّىْءَ فِي الصَّلاَةِ
Narrated Abu Huraira:
People say that I narrate too many narrations of the Prophet; once I met a man (during the lifetime of the Prophet) and asked him, "Which Sura did Allah's Messenger (ﷺ) s recite yesterday in the `Isha' prayer?" He said, "I do not know." I said, "Did you not attend the prayer?" He said, "Yes, (I did)." I said, "I know. He recited such and such Sura."
Reference: Sahih al-Bukhari 1223
In-book reference: Book 21, Hadith 27
USC-MSA web (English) reference(deprecated numbering scheme): Vol. 2, Book 22, Hadith 314