Fussilat - 41:5

وَقَالُوا قُلُوبُنَا فِي أَكِنَّةٍ مِّمَّا تَدْعُونَا إِلَيْهِ وَفِي آذَانِنَا وَقْرٌ وَمِن بَيْنِنَا وَبَيْنِكَ حِجَابٌ فَاعْمَلْ إِنَّنَا عَامِلُونَ
[41:5]
And they say: Our hearts are under coverings from that to which you call us, and there is a heaviness in our ears, and a veil hangs between us and you, so work, we too are working.
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!)"
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.