Narrated Abu Huraira (may Allah be pleased with him) that the Messenger of Allah (peace and blessings of Allah be upon him) said: "The wrath of Allah became extremely severe upon the people who did this to their Prophet." He was referring to the breaking of the front blessed teeth. "The wrath of Allah became extremely severe upon the person (Ubayy bin Khalaf) whom His Prophet (peace and blessings of Allah be upon him) killed in the way of Allah."