The Prophet ﷺ said, "Whoever intentionally swears falsely by a religion other than Islam, then he is what he has said, (e.g. if he says, 'If such thing is not true then I am a Jew,' he is really a Jew). And whoever commits suicide with piece of iron will be punished with the same piece of iron in the Hell Fire." Narrated Jundab the Prophet ﷺ said, "A man was inflicted with wounds and he committed suicide, and so Allah said: My slave has caused death on himself hurriedly, so I forbid Paradise for him."  

عَنِ النَّبِيِّ ﷺ قَالَ مَنْ حَلَفَ بِمِلَّةٍ غَيْرِ الإِسْلاَمِ كَاذِبًا مُتَعَمِّدًا فَهُوَ كَمَا قَالَ وَمَنْ قَتَلَ نَفْسَهُ بِحَدِيدَةٍ عُذِّبَ بِهِ فِي نَارِ جَهَنَّمَ وَقَالَ حَجَّاجُ بْنُ مِنْهَالٍ حَدَّثَنَا جَرِيرُ بْنُ حَازِمٍ عَنِ الْحَسَنِ حَدَّثَنَا جُنْدَبٌ ؓ فِي هَذَا الْمَسْجِدِ فَمَا نَسِينَا وَمَا نَخَافُ أَنْ يَكْذِبَ جُنْدَبٌ عَنِ النَّبِيِّ ﷺ قَالَ كَانَ بِرَجُلٍ جِرَاحٌ فَقَتَلَ نَفْسَهُ فَقَالَ اللَّهُ بَدَرَنِي عَبْدِي بِنَفْسِهِ حَرَّمْتُ عَلَيْهِ الْجَنَّةَ  

The Prophet ﷺ said, "He who commits suicide by throttling shall keep on throttling himself in the Hell Fire (forever) and he who commits suicide by stabbing himself shall keep on stabbing himself in the Hell-Fire."  

قَالَ النَّبِيُّ ﷺ الَّذِي يَخْنُقُ نَفْسَهُ يَخْنُقُهَا فِي النَّارِ وَالَّذِي يَطْعُنُهَا يَطْعُنُهَا فِي النَّارِ