The Prophet ﷺ said: People who get up from an assembly in which they did not remember Allah will be just as if they had got up from an ass's corpse, and it will be a cause of grief to them.  

قَالَ رَسُولُ اللَّهِ ﷺ مَا مِنْ قَوْمٍ يَقُومُونَ مِنْ مَجْلِسٍ لاَ يَذْكُرُونَ اللَّهَ فِيهِ إِلاَّ قَامُوا عَنْ مِثْلِ جِيفَةِ حِمَارٍ وَكَانَ لَهُمْ حَسْرَةً  

The Prophet ﷺ said: If anyone sits at a place where he does not remember Allah, deprivation will descend on him from Allah; and if he lies at a place where he does not remember Allah, deprivation will descend on him from Allah.  

عَنْ رَسُولِ اللَّهِ ﷺ أَنَّهُ قَالَ مَنْ قَعَدَ مَقْعَدًا لَمْ يَذْكُرِ اللَّهَ فِيهِ كَانَتْ عَلَيْهِ مِنَ اللَّهِ تِرَةً وَمَنِ اضْطَجَعَ مَضْجَعًا لاَ يَذْكُرُ اللَّهَ فِيهِ كَانَتْ عَلَيْهِ مِنَ اللَّهِ تِرَةً