Surah Al-An'am, ayah 25

وَمِنۡهُم مَّن يَسۡتَمِعُ إِلَيۡكَۖ وَجَعَلۡنَا عَلَىٰ قُلُوبِهِمۡ أَكِنَّةً أَن يَفۡقَهُوهُ وَفِيٓ ءَاذَانِهِمۡ وَقۡرٗاۚ وَإِن يَرَوۡاْ كُلَّ ءَايَةٖ لَّا يُؤۡمِنُواْ بِهَاۖ حَتَّىٰٓ إِذَا جَآءُوكَ يُجَٰدِلُونَكَ يَقُولُ ٱلَّذِينَ كَفَرُوٓاْ إِنۡ هَٰذَآ إِلَّآ أَسَٰطِيرُ ٱلۡأَوَّلِينَ ٢٥

Waminhum man yastami'u ilayka waja'alnā 'alā qulūbihim akinnatan an yafqahūhu wafī ādhānihim waqran wa in yaraw kulla āyatil lā yu'minū bihā hattā idhā jā'ūka yujādilūnaka yaqūlul-ladhīna kafarū in hādhā illā asātīrul-awwalīn

And among them are those who listen to you,³⁰⁰ but We have placed over their hearts coverings, lest they understand it, and in their ears deafness. And if they should see every sign, they will not believe in it. Even when they come to you arguing with you, those who disbelieve say, "This is not but legends of the former peoples."