Musnad Abu Ya'la al-Mawsili 150:242

Isma'il ibn Musa narrated to us, Ibn Abi al-Zinad narrated to us, from his father, from 'Urwah, from 'Aishah, who said: The Messenger of Allah (may Allah bless him and grant him peace) used to place a pulpit in the mosque for Hassan. He would stand upon it, boasting on behalf of the Messenger of Allah or defending him. And the Messenger of Allah (may Allah bless him and grant him peace) would say: "Indeed, Allah supports Hassan with the Holy Spirit as long as he defends or boasts on behalf of the Messenger of Allah."