This tradition has been narrated on the authority of Salama who said
We fought by the side of the Messenger of Allah (ﷺ) at Hunain. When we encountered the enemy, I advanced and ascended a hillock. A man from the enemy side turned towards me and I shot him with an arrow. He (ducked and) hid himself from me. I could not understand what he did, but (all of a sudden) I saw that a group of people appeared from the other hillock. They and the Companions of the Prophet (ﷺ) met in combat, but the Companions of the Prophet turned back and I too turned back defeated. I had two mantles, one of which I was wrapping round the waist (covering the lower part of my body) and the other I was putting around my shoulders. My waist-wrapper got loose and I held the two mantles together. (In this downcast condition) I passed by the Messenger of Allah (ﷺ) who was riding on his white mule. He said: The son of Akwa' finds himself to be utterly perplexed. Wher. the Companions gathered round him from all sides. the Messenger of Allah (ﷺ) got down from his mule. picked up a handful of dust from the ground, threw it into their (enemy) faces and said: May these faces be deformed 1 There was no one among the enemy whose eyes were not filled with the dust from this handful. So they turned back fleeing. and Allah the Exalted and Glorious defeated them, and the Messenger of Allah (ﷺ) distributed their booty among the Muslims.