Sahih Bukhari Volume 4, Book 54, Hadith Number 434.

Narated By Sa’id bin Al-Musaiyab : ‘Umar came to the Mosque while Hassan was reciting a poem. (‘Umar disapproved of that). On that Hassan said, “I used to recite poetry in this very Mosque in the presence of one (i.e. the Prophet) who was better than you.” Then he turned towards Abu Huraira and said (to him), “I ask you by Allah, did you hear Allah’s Apostle saying (to me), “Retort on my behalf. O Allah! Support him (i.e. Hassan) with the Holy Spirit?” Abu Huraira said, “Yes.”