Sayyiduna Abu Hurayrah (may Allah be pleased with him) narrated that the Messenger of Allah (peace and blessings be upon him) said: "None of you should point a weapon at his brother, for it is possible that Satan causes his hand to slip and the weapon strikes his brother, as a result of which the one who struck becomes fuel for Hell."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الجنايات / 15872