Surah Al-'Ankabut (29:3)
وَلَقَدْ فَتَنَّا ٱلَّذِينَ مِن قَبْلِهِمْ فَلَيَعْلَمَنَّ ٱللَّهُ ٱلَّذِينَ صَدَقُوا۟ وَلَيَعْلَمَنَّ ٱلْكَٰذِبِينَ
And We have indeed tested those before them, so that Allah will surely know those who have been truthful and will surely know the liars.
Roots in this verse: ف ت ن (ftn), ق ب ل (qbl), ع ل م (Elm), ا ل ه (Alh), ص د ق (Sdq), ك ذ ب (k*b)