خَلْف

فَجَعَلْنَـٰهَا نَكَـٰلًۭا لِّمَا بَيْنَ يَدَيْهَا وَمَا خَلْفَهَا وَمَوْعِظَةًۭ لِّلْمُتَّقِينَ

And We made it a deterrent punishment for those who were present and those who succeeded [them] and a lesson for those who fear Allāh.

فَإِمَّا تَثْقَفَنَّهُمْ فِى ٱلْحَرْبِ فَشَرِّدْ بِهِم مَّنْ خَلْفَهُمْ لَعَلَّهُمْ يَذَّكَّرُونَ

So if you, [O Muḥammad], gain dominance over them in war, disperse by [means of] them those behind them that perhaps they will be reminded.

يَعْلَمُ مَا بَيْنَ أَيْدِيهِمْ وَمَا خَلْفَهُمْ وَلَا يُحِيطُونَ بِهِۦ عِلْمًۭا

He [i.e., Allāh] knows what is [presently] before them and what will be after them, but they do not encompass it [i.e., what He knows] in knowledge.