﴿ ۞ أَوَلَمْ يَسِيرُوا۟ فِى ٱلْأَرْضِ فَيَنظُرُوا۟ كَيْفَ كَانَ عَٰقِبَةُ ٱلَّذِينَ كَانُوا۟ مِن قَبْلِهِمْ ۚ كَانُوا۟ هُمْ أَشَدَّ مِنْهُمْ قُوَّةًۭ وَءَاثَارًۭا فِى ٱلْأَرْضِ فَأَخَذَهُمُ ٱللَّهُ بِذُنُوبِهِمْ وَمَا كَانَ لَهُم مِّنَ ٱللَّهِ مِن وَاقٍۢ ﴾

“Have they, then, never journeyed about the earth and beheld what happened in the end to those [deniers of the truth] who lived before their time? Greater were they in power than they are, and in the impact which they left on earth: but God took them to task for their sins, and they had none to defend them against God:”

In verse 19, it was said: يَعْلَمُ خَائِنَةَ الْأَعْيُنِ (He knows the treachery of the eyes), in other words, eyes that betray the trust. It means the action of a person who would, secretly and surreptitiously, cast a glance over something haram and impermissible for him or her, for example, casts a glance at a non-mahram person with sexual desire, and takes it away in the event someone was around, or casts a glance in a manner that is not noticed by others. All these things are open before Allah Ta’ ala.