Sayyiduna Abdullah bin Abbas (may Allah be pleased with them both) said: Al-Fadl bin Abbas (may Allah be pleased with him) was riding behind the Prophet (peace and blessings be upon him), and the young man began glancing at the women and looking towards them. The Messenger of Allah (peace and blessings be upon him) began turning his face away with his hand from behind, and the young man kept looking towards them again and again. So the Messenger of Allah (peace and blessings be upon him) said to him: "This is a day on which whoever controls his hearing, his sight and his tongue will be forgiven."
Hadith Referenceالمعجم الكبير للطبراني / باب العين / 12918