Sahih al-Bukhari, Book 64, Hadith 168 (In-Book) ⓘ
Al-Bara' bin `Azib said (through another chain of sub-narrators): "On the day of Quraiza's (siege), Allah's Messenger said to Hassan bin Thabit, 'Abuse them (with your poems), and Jibril is with you.'"
وَزَادَ إِبْرَاهِيمُ بْنُ طَهْمَانَ عَنِ الشَّيْبَانِيِّ، عَنْ عَدِيِّ بْنِ ثَابِتٍ، عَنِ الْبَرَاءِ بْنِ عَازِبٍ، قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم يَوْمَ قُرَيْظَةَ لِحَسَّانَ بْنِ ثَابِتٍ " اهْجُ الْمُشْرِكِينَ، فَإِنَّ جِبْرِيلَ مَعَكَ " .
also referenced under: Hadith 4124 (DarusSalam) & Volume 5, Book 59, Hadith 449 (USC-MSA)