Qur'an 41:5

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

And they say: Our hearts are protected from that unto which thou (O Muhammad) callest us, and in our ears there is a deafness, and between us and thee there is a veil. Act, then. Lo! we also shall be acting.