Musnad Ahmad 30:3760

Hammad al-Khayyat narrated to us, Hisham bin Sa'd narrated to us, from Nu'aym bin 'Abdullah al-Mujmir, from Abu Hurayrah, who said: The Messenger of Allah (peace and blessings of Allah be upon him) went out to the market of Banu Qaynuqa', leaning on my hand. He walked around in it, then returned and sat with his legs drawn up to his abdomen (ihtaba) in the mosque. He said: "Where is the little boy (luka')? Call the little boy for me." Al-Hasan came, running until he jumped into his lap. He (the Prophet) put his mouth into his mouth, then said: "O Allah, I love him, so love him, and love whoever loves him," (repeating it) three times. Abu Hurayrah said: "I have never seen Al-Hasan but that my eyes overflowed—or my eyes teared up, or I wept," (the narrator Al-Khayyat was uncertain).