Sahih Muslim Book 32, Hadith Number 6338.

Chapter : The prohibition of pointing a weapon towards a Muslim.

Abu Huraira reported a hadith from Allah’s Messenger (may peace be upon him); (one of them was this) that Allah’s Messenger (may peace be upon him) said: None amongst you should point a weapon towards his brother, for he does not know that Satan might cause the weapon (to slip) from his hand and (he may injure anyone) and thus he may fall into Hell-Fire.