Sura Fuṣṣilat 41:5

وَقَالُوا۟ قُلُوبُنَا فِىٓ أَكِنَّةٍ مِّمَّا تَدْعُونَآ إِلَيْهِ وَفِىٓ ءَاذَانِنَا وَقْرٌ وَمِنۢ بَيْنِنَا وَبَيْنِكَ حِجَابٌ فَٱعْمَلْ إِنَّنَا عَٰمِلُونَ

wa-qālū qulūbunā fī akinnatin mimmā tadʿūnā ilayhi wa-fī ādhāninā waqrun wa-min bayninā wa-baynika ḥijābun fa-iʿmal innanā ʿāmilūna

They say: "Our hearts are under veils, (concealed) from that to which thou dost invite us, and in our ears in a deafness, and between us and thee is a screen: so do thou (what thou wilt); for us, we shall do (what we will!)"