Hisham bin Urwah (may Allah have mercy on him) narrates from his father that Aishah (may Allah be pleased with her) said that the Messenger of Allah (peace and blessings be upon him) heard a man reciting at night. He (peace and blessings be upon him) said: 'Yarhamuhullah' "May Allah have mercy on him; he has reminded me of a verse of such-and-such a surah."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصلاة / 4707