Khwaja Hasan (may Allah have mercy on him) says that Hazrat Abu Musa (may Allah be pleased with him) had a brother who used to take an active part in acts of discord. He (Abu Musa) would forbid him, but he would not desist. He would say to him: "If I thought that even a little advice would be enough for you, which in my opinion is less than this (I would still advise you)." And the Noble Prophet (peace and blessings be upon him) said: "When two Muslims come face to face with swords and one of them kills the other, then both the killer and the killed will go to Hell."