ENOfficial
It was narrated from Abdullah bin Buraidah that his father told that : the Messenger of Allah (ﷺ) said: "Whoever says: 'I have nothing to do with Islam,' if he is lying then he is as he said, and if he is telling the truth, his Islam will not be sound."
Source: sunnah.com
Other translations
Arabic
حَدَّثَنَا عَمْرُو بْنُ رَافِعٍ الْبَجَلِيُّ، حَدَّثَنَا الْفَضْلُ بْنُ مُوسَى، عَنِ الْحُسَيْنِ بْنِ وَاقِدٍ، عَنْ عَبْدِ اللَّهِ بْنِ بُرَيْدَةَ، عَنْ أَبِيهِ، قَالَ قَالَ رَسُولُ اللَّهِ ـ صلى الله عليه وسلم ـ " مَنْ قَالَ إِنِّي بَرِيءٌ مِنَ الإِسْلاَمِ فَإِنْ كَانَ كَاذِبًا فَهُوَ كَمَا قَالَ وَإِنْ كَانَ صَادِقًا لَمْ يَعُدْ إِلَيْهِ الإِسْلاَمُ سَالِمًا " .
sunnah.com