"Whoever swears by a religion other than Islam, telling a lie, will be as he said, and whoever kills himself with something will be punished with it in the Hereafter." (Using translation from Nasāʾī 3771)
أَنَّ رَسُولَ اللهِ ﷺ قَالَ «مَنْ حَلَفَ بِمِلَّةٍ سِوَى الْإِسْلَامِ كَاذِبًا فَهُوَ كَمَا قَالَ وَمَنْ ذَبَحَ نَفْسَهُ بِشَيْءٍ ذُبِحَ بِهِ يَوْمَ الْقِيَامَةِ»