أَفِى قُلُوبِهِم مَّرَضٌ أَمِ ٱرْتَابُوٓا۟ أَمْ يَخَافُونَ أَن يَحِيفَ ٱللَّهُ عَلَيْهِمْ وَرَسُولُهُۥ ۚ بَلْ أُو۟لَـٰٓئِكَ هُمُ ٱلظَّـٰلِمُونَ Qur’an An-Nur (24:50)Afee quloobihim maradun ami irtaboo am yakhafoona an yaheefa Allahu AAalayhim warasooluhu bal olaika humu alththalimoona
I.e., by depriving them of what they choose to regard as "legitimate" liberties and enjoyments, or by supposedly preventing them from "keeping up with the times". As in verses {47} and {48} (as well as in verse {51} below) the expression "God and His Apostle" is here a synonym for the divine writ revealed to the Apostle.
The real fact is that their conscience smites them. They know their own iniquity, and do not wish to go before a just judge who would be open to no influence and would be sure to give a righteous decree.