The Prophet (peace and blessings be upon him) said: "O Allah, I have made a covenant with You which You will never break: I am only a human being, so whichever believer I rebuke, reproach, strike or curse, make it for him a mercy, a purification and a means of nearness to You on the Day of Resurrection."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب النكاح / 13380