It was
narrated from Jabir bin Samurah that a man from among the
Companions
of the Prophet (ﷺ) was wounded, and the wound caused him
a great
deal of pain. He went and took a spearhead, and slaughtered
himself
with it. The Prophet (ﷺ) did not offer the funeral prayer
for him,
and that was as an admonition for others.
Sunan Ibn Majah Book 6, Hadith 94