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."
English reference: Vol. 3, Book 11, Hadith 2100
Arabic reference: Book 11, Hadith 2178