It is narrated from Sayyiduna Dukayn bin Sa'id al-Muzani (may Allah be pleased with him); he said: We came to the Messenger of Allah (peace and blessings be upon him) asking for food, and we were four hundred riders. Then the narrator mentioned a hadith like it.
Hadith Referenceالمعجم الكبير للطبراني / باب الدال / 4193