“Whoever gestures to his brother with a piece of iron, the angels curse him until he desists, even if he is his paternal and maternal brother.”

Narrated by Muslim (no. 2616), from the narration of Abū Hurayrah — may Allah be pleased with him.

Brief Explanation of the Hadith

Islamic law safeguards human life and preserves it, considering this one of the greatest foundations and objectives of the religion. A clear evidence of this is the Prophet’s — may Allah’s peace and blessings be upon him — statement: “Whoever gestures to his brother with an iron weapon, the angels curse him.”
Cursing means being expelled and distanced from the mercy of Allah Almighty, and the angels continue to curse him until he puts down his weapon — even if the one he gestures toward is his own brother from his father and mother. This is an emphatic warning and deterrent, for such an act may lead to the taking of lives, may Allah forbid.
The cursing here indicates the severity of the prohibition, and that this act is among the major sins — whether the person does it seriously or in jest. If serious, he truly intends harm; and if joking, he has nonetheless terrified a Muslim. The Sharīʿah has forbidden frightening a Muslim even in jest, as it is a means that may lead to falling into what is unlawful. As mentioned in another narration: “Perhaps Satan may snatch it from his hand, and he may fall into a pit of the Fire.” Meaning: the weapon may slip from his hand unintentionally and harm his brother, or even kill him, thus causing him to fall into a grave major sin.
Islam did not prohibit only killing; rather, it blocked every means leading to it, even in the form of jest, in order to safeguard the sanctity of the Muslim and protect society from causes of enmity and fighting.
The ḥadīth contains a severe warning and an emphatic admonition against being negligent in the matter of handling weapons, for merely pointing with it is deemed a major sin that incurs the curse—so how much greater is the sin of killing itself?