Sayyiduna Usamah bin Sharik (may Allah be pleased with him) said: A group of Bedouins with swords slung on them came to the Prophet (peace and blessings be upon him) and crowded over him asking questions, so we became anxious for (the safety of) the Prophet (peace and blessings be upon him) and drew close to them. The narrator said: I heard them saying: Is there any harm upon us in such-and-such? Is there any harm upon us in such-and-such? The Messenger of Allah (peace and blessings be upon him) said: "O people, Allah has removed harm, except for the one who assails the honour of his Muslim brother; he is the one who has fallen into harm and is ruined." They said: O Messenger of Allah, should we seek treatment for such-and-such an illness? He (peace and blessings be upon him) said: "Seek treatment, for Allah, the Mighty and Majestic, has not sent down any disease without also sending down its remedy, except old age." They said: O Messenger of Allah, what is the best thing a Muslim servant has been given in this world? He (peace and blessings be upon him) said: "Good character."
Hadith Referenceالمعجم الكبير للطبراني / باب الألف / 477