The Prophet ﷺ said to Hassan, "Satirize them, or attack them in verse, for Jibreel is with you."
قال النبي ﷺ لحسان: اهجهم أو هاجمهم- وجبريل معك.
Bukhari narrated it in the Book of Military Expeditions (4123), and Muslim in the Book of the Virtues of the Companions (153:2486), both through the route of Shubah, who said, Adi bin Thabit told me, he said, I heard Bara bin Azib say, then he related it. In the version narrated by Bukhari, he said this on the day of Qurayza.