Abu Umamah bin Sahl bin Hunayf narrated that his father, Sayyiduna Sahl bin Hunayf (may Allah be pleased with him), said: "O my son, I saw us on the day of Badr in such a state that one of us would merely point his sword towards the head of an idolater, and his head would fall from his body before (the sword) reached it."
Hadith Referenceالمعجم الكبير للطبراني / باب السين / 5535