Hadithcore
Sunan Ibn Majah, 1526
sahih· Darussalam

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.

حَدَّثَنَا عَبْدُ اللَّهِ بْنُ عَامِرِ بْنِ زُرَارَةَ، حَدَّثَنَا شَرِيكُ بْنُ عَبْدِ اللَّهِ، عَنْ سِمَاكِ بْنِ حَرْبٍ، عَنْ جَابِرِ بْنِ سَمُرَةَ، أَنَّ رَجُلاً، مِنْ أَصْحَابِ النَّبِيِّ ـ صلى الله عليه وسلم ـ جُرِحَ فَآذَتْهُ الْجِرَاحَةُ فَدَبَّ إِلَى مَشَاقِصِهِ فَذَبَحَ بِهِ نَفْسَهُ فَلَمْ يُصَلِّ عَلَيْهِ النَّبِيُّ ـ صلى الله عليه وسلم ـ ‏.‏ قَالَ وَكَانَ ذَلِكَ أَدَبًا مِنْهُ ‏.‏

References2 variants
In-Book Reference
Book 6, Hadith 94
English Reference
Vol. 1, Book 6, Hadith 1526