Surah Fussilat, ayah 5

وَقَالُواْ قُلُوبُنَا فِيٓ أَكِنَّةٖ مِّمَّا تَدۡعُونَآ إِلَيۡهِ وَفِيٓ ءَاذَانِنَا وَقۡرٞ وَمِنۢ بَيۡنِنَا وَبَيۡنِكَ حِجَابٞ فَٱعۡمَلۡ إِنَّنَا عَٰمِلُونَ ٥

Waqālū qulūbunā fī akinnatim mimmā tad'ūnā ilayhi wafī ādhāninā waqrun wamim bayninā wabaynika hijābun fa'mal innanā 'āmilūn

And they say, "Our hearts are within coverings [i.e., screened] from that to which you invite us, and in our ears is deafness, and between us and you is a partition, so work;¹³⁸³ indeed, we are working."