Surah Al-Kahf, Verse 5
مَّا لَهُم بِهِۦ مِنْ عِلْمٍۢ وَلَا لِءَابَآئِهِمْ ۚ كَبُرَتْ كَلِمَةًۭ تَخْرُجُ مِنْ أَفْوَٰهِهِمْ ۚ إِن يَقُولُونَ إِلَّا كَذِبًۭا
Translation — Sahih International
They have no knowledge of it, nor had their fathers. Grave is the word that comes out of their mouths; they speak not except a lie.
Source
Kur'an-ı Kerim, Kehf Suresi 18:5
https://kuran.diyanet.gov.tr/mushaf/kuran-meal-2/18-suresi-5-ayet