The Messenger of Allah ﷺ said, "Whoever falsely swears by a religion other than Islam is as he said." Qutayba's version says "intentionally," while Yazid's version says "falsely, then he is as he said." "And whoever kills himself with something, Allah will torment him with it in the Fire of Hell."
أخبرنا قتيبة قال حدثنا ابن أبي عدي عن خالد ح وأنبأنا محمد بن عبد الله بن بزيع قال حدثنا يزيد قال حدثنا خالد عن أبي قلابة
قال رسول الله ﷺ من حلف بملة سوى الإسلام كاذبا فهو كما قال قال قتيبة في حديثه متعمدا وقال يزيد كاذبا فهو كما قال ومن قتل نفسه بشيء عذبه الله به في نار جهنم
Bukhari narrated it in the Book of Funerals, the chapter on what has been said about one who kills himself, hadith no. 1363, from the hadith of Yazid bin... etc., hadith no. 177/110, from Zuray, and Muslim narrated it in the Book of Faith, the chapter on the statement of the severity of the prohibition against a person killing himself, the hadith of Khalid Haddan, with this wording, and it is also in Al-Kubra, hadith no. 4711.