عَنِ ابْنِ بُرَيْدَةَ عَنْ أَبِيهِ رَضِيَ اللَّهُ عَنْهُ قَالَ قَالَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَآلِهِ وَسَلَّمَ مَنْ حَلَفَ أَنَّهُ بَرِيءٌ مِنَ الْإِسْلَامِ فَإِنْ كَانَ كَاذِبًا فَهُوَ كَمَا قَالَ وَإِنْ كَانَ صَادِقًا فَلَنْ يَرْجِعَ إِلَى الْإِسْلَامِ سَالِمًا
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.