صحيح مسلم

Abu Huraira reported that 'Umar happened to pass by Hassan as he was reciting verses in the mosque. He (Hadrat 'Umar) looked towards him (meaningfully), whereupon he (gassin) said: I used to recite (verses) when one better than you (the Holy Prophet) had been present (here). He then looked towards Abu Huraira and said to him: I adjure you by Allah (to tell) if you had not heard Allah's Messenger (ﷺ) as saying: (Hassan), give a reply on my behalf; Allah I help him with Ruh-ul-Qudus. He (Abu Huraira) said: By Allah, it is so (i. e. the Prophet (ﷺ) actually said these words).