It is narrated from Sayyiduna Yazid bin Amir al-Suwa'i (may Allah be pleased with him); he said: When the Muslims faced a retreat on the day of Hunayn and the disbelievers pursued them, the Messenger of Allah (peace and blessings be upon him) took a handful of earth from the ground, threw it towards their faces and said: "Turn back! May the faces be disfigured!" Then every one of us who met his brother was complaining of a speck in his eye and rubbing his eyes.
Hadith Referenceالمعجم الكبير للطبراني / باب الياء / 18842