Sayyiduna Aswad bin Asram al-Muharibi (may Allah be pleased with him) narrates: I said: "O Messenger of Allah! Advise me." He (peace and blessings be upon him) said: "Do you have control over your hand?" I said: "If I do not have control over my hand, then what will I have control over?" He (peace and blessings be upon him) said: "Do you have control over your tongue?" I said: "If I do not have control over my tongue, then what will I have control over?" He (peace and blessings be upon him) said: "Do not stretch out your hand except towards what is good, and do not say anything with your tongue except what is good."
Hadith Referenceالمعجم الكبير للطبراني / باب الألف / 814