The Messenger of Allah ﷺ heard a man reciting a surah at night, so he said, "May Allah have mercy on him. He has reminded me of such-and-such verses that I had forgotten from surah such-and-such."
سمع رسول الله رجلا ﷺ يقرأ في سورة بالليل فقال: يرحمه الله لقد أذكرني كذا وكذا آية كنت أنسيتها من سورة كذا وكذا.
Bukhari narrated it in the Virtues of the Quran (5038) and Muslim in the Prayer of Travelers (788), both from the hadith of Abu Usama, from Hisham bin Urwa, from his father, from Ayesha, and I have already mentioned it. The wording given is Bukhari's, while Muslim's wording is, "I had dropped it from such and such surah." In the narration of Abda and Abu Muawiya from Hisham, it reads, "I had forgotten it." Its detailed sourcing was given earlier in the Night Prayer, in the chapter on raising the voice in night prayer.