وَلَقَدْ فَتَنَّا ٱلَّذِينَ مِن قَبْلِهِمْ ۖ فَلَيَعْلَمَنَّ ٱللَّهُ ٱلَّذِينَ صَدَقُوا۟ وَلَيَعْلَمَنَّ ٱلْكَٰذِبِينَ

And certainly We tried those before them, so Allah will certainly know those who are true and He will certainly know the liars.