Verse 28

بَلْ بَدَا لَهُم مَّا كَانُوا۟ يُخْفُونَ مِن قَبْلُ وَلَوْ رُدُّوا۟ لَعَادُوا۟ لِمَا نُهُوا۟ عَنْهُ وَإِنَّهُمْ لَكَـٰذِبُونَ

This is because what they used to hide in the past was shown to them, and had they returned, they would have reverted to what they were enjoined to avoid, and indeed they are liars.