They were having a problem distinguishing between what was clean and what was unclean, and this involved their conscience.
يُعْلِنُونَ جَهْرًا أَنَّهُمْ يَعْرِفُونَ ٱللهَ ،‏ لٰكِنَّهُمْ بِأَعْمَالِهِمْ يُنْكِرُونَهُ كُلِّيًّا » .‏