Qur'an 47:16

وَمِنْهُم مَّن يَسْتَمِعُ إِلَيْكَ حَتَّىٰٓ إِذَا خَرَجُوا۟ مِنْ عِندِكَ قَالُوا۟ لِلَّذِينَ أُوتُوا۟ ٱلْعِلْمَ مَاذَا قَالَ ءَانِفًا ۚ أُو۟لَـٰٓئِكَ ٱلَّذِينَ طَبَعَ ٱللَّهُ عَلَىٰ قُلُوبِهِمْ وَٱتَّبَعُوٓا۟ أَهْوَآءَهُمْ

Among them are some who give ear unto thee (Muhammad) till, when they go forth from thy presence they say unto those who have been given knowledge: What was that he said just now? Those are they whose hearts Allah hath sealed, and they follow their own lusts.