(21) باب إِذَا قَالَ عِنْدَ قَوْمٍ شَيْئًا ثُمَّ خَرَجَ فَقَالَ بِخِلاَفِهِ
Narrated Abi Asha'sha:
Hudhaifa said, 'In fact, it was hypocrisy that existed in the lifetime of the Prophet (ﷺ) but today it is Kufr (disbelief) after belief.'
Reference: Sahih al-Bukhari 7114
In-book reference: Book 92, Hadith 61
USC-MSA web (English) reference(deprecated numbering scheme): Vol. 9, Book 88, Hadith 230