It is narrated from Sayyiduna Buraidah (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) said: Whoever swears an oath that he will be free from Islam, if he is lying, then he will become as he said; and if he is truthful, then he will not return safely to Islam.
Hadith Referenceالفتح الربانی / كتاب الأيمان والنذور / 5305
Hadith Gradingمحدثین:صحیح
Hadith Takhrij«اسناده قوي، أخرجه ابوداود: 3258، والنسائي:7/6، وابن ماجه: 2100، (انظر مسند أحمد ترقيم الرسالة: 23006 ترقیم بيت الأفكار الدولية: 23394»
Brief Explanation
Benefits: … The form of this type is that a person says: “If I have done such-and-such act, then I become a Jew or a Christian, etc., or I am free from Islam,” while in fact he has done that act and he also remembers it. Or he says: “If I do this act, then I become a Jew or a Christian, or I am finished with Islam,” while his intention is that he will indeed do that act, and he swears only for the purpose of deception.