adab 43 Asking Permission كتاب الاسْتِئْذَانُ 21

وَقَالَ النَّبِيُّ صلى الله عليه وسلم: إِنَّمَا جُعِلَ الإِذْنُ مِنْ أَجْلِ الْبَصَرِ.

The Prophet, may Allah bless him and grant him peace, said, “The ear is put in the place of the eye.”