أَفَلَمْ يَسِيرُوا فِي الْأَرْضِ فَتَكُونَ لَهُمْ قُلُوبٌ يَعْقِلُونَ بِهَا أَوْ آذَانٌ يَسْمَعُونَ بِهَا ۖ فَإِنَّهَا لَا تَعْمَى الْأَبْصَارُ وَلَٰكِنْ تَعْمَى الْقُلُوبُ الَّتِي فِي الصُّدُورِ

What, have they not journeyed in the land so that they have hearts to understand with or ears to hear with? It is not the eyes that are blind, but blind are the hearts within the breasts.