Ibn Shihab narrated that among those of the Ansar who took part in Badr, then from Banu al-Harith bin al-Khazraj, is the name of Sayyiduna Sa'd bin al-Rabi' (may Allah be pleased with him). He was a naqib (chief representative).
Hadith Referenceالمعجم الكبير للطبراني / باب السين / 5378