Sayyiduna Sulaym bin Jabir (may Allah be pleased with him) narrates: I heard about the Prophet (peace and blessings be upon him), so I had my mount brought and said: "I will certainly go to this man and hear from him." So I came to him and found him sitting with his knees drawn up in a cloak, and I heard him (peace and blessings be upon him) replying to a questioner: "Never regard any good deed as insignificant, even if it is that you pour the leftover water of your bucket into the vessel of one seeking water. And beware of letting the lower garment hang down, for it is part of arrogance, and Allah does not love arrogance. And if a man insults you, or says about you something that is not in you, then do not insult him, and do not say about him something that is not in him, so that its reward will be yours and its evil consequence will be upon him. Never revile anyone." The narrator says: Ever since I heard the Messenger of Allah (peace and blessings be upon him) forbid reviling, I have not reviled anything, neither a camel, nor a goat, nor a human being.
Hadith Referenceالمعجم الكبير للطبراني / باب السين / 6358