Verily the Messenger of Allah ﷺ said: He who took an oath on a religion other than Islam as a liar would become so as he said, and he who slaughtered himself with a thing would be slaughtered with that on the Day of Resurrection.
قَالَ النَّبِيُّ ﷺ مَنْ حَلَفَ بِمِلَّةٍ سِوَى الإِسْلاَمِ كَاذِبًا مُتَعَمِّدًا فَهُوَ كَمَا قَالَ وَمَنْ قَتَلَ نَفْسَهُ بِشَىْءٍ عَذَّبَهُ اللَّهُ بِهِ فِي نَارِ جَهَنَّمَ هَذَا حَدِيثُ سُفْيَانَ وَأَمَّا شُعْبَةُ فَحَدِيثُهُ أَنَّ رَسُولَ اللَّهِ ﷺ قَالَ مَنْ حَلَفَ بِمِلَّةٍ سِوَى الإِسْلاَمِ كَاذِبًا فَهُوَ كَمَا قَالَ وَمَنْ ذَبَحَ نَفْسَهُ بِشَىْءٍ ذُبِحَ بِهِ يَوْمَ الْقِيَامَةِ