Sunan an-Nasa'i, Book 21, Hadith 148 (In-Book) ⓘ
It was narrated from Jabir bin Samurah that: a man killed himself with an arrowhead and the Messenger of Allah said: "As for me, I will not pray for him."
أَخْبَرَنَا إِسْحَاقُ بْنُ مَنْصُورٍ، قَالَ أَنْبَأَنَا أَبُو الْوَلِيدِ، قَالَ حَدَّثَنَا أَبُو خَيْثَمَةَ، زُهَيْرٌ قَالَ حَدَّثَنَا سِمَاكٌ، عَنِ جَابِرِ بْنِ سَمُرَةَ، أَنَّ رَجُلاً، قَتَلَ نَفْسَهُ بِمَشَاقِصَ فَقَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم " أَمَّا أَنَا فَلاَ أُصَلِّي عَلَيْهِ " .
also referenced under: Hadith 1964 (Reference) & Volume 3, Book 21, Hadith 1966 (DarusSalam)