Sahl b. Sa'd as-Sa'id reported that a person peeped through the hole of the door of Messenger of Allah ﷺ, and at that time Messenger of Allah ﷺ had with him a scratching instrument with which he had been scratching his head. When Messenger of Allah ﷺ saw him. he said: If I were to know that you had been peeping through the door, I would have thrust that into your eyes, and Messenger of Allah ﷺ said: Permission is needed as a protection against glance.

حَدَّثَنَا يَحْيَى بْنُ يَحْيَى، وَمُحَمَّدُ بْنُ رُمْحٍ، قَالاَ أَخْبَرَنَا اللَّيْثُ، - وَاللَّفْظُ لِيَحْيَى -
ح وَحَدَّثَنَا قُتَيْبَةُ بْنُ سَعِيدٍ، حَدَّثَنَا لَيْثٌ، عَنِ ابْنِ شِهَابٍ، أَنَّ سَهْلَ بْنَ سَعْدٍ السَّاعِدِيَّ، أَخْبَرَهُ
أَنَّ رَجُلاً اطَّلَعَ فِي جُحْرٍ فِي بَابِ رَسُولِ اللَّهِ ﷺ وَمَعَ رَسُولِ اللَّهِ صلى
الله عليه وسلم مِدْرًى يَحُكُّ بِهِ رَأْسَهُ فَلَمَّا رَآهُ رَسُولُ اللَّهِ ﷺ قَالَ "
لَوْ أَعْلَمُ أَنَّكَ تَنْظُرُنِي لَطَعَنْتُ بِهِ فِي عَيْنِكَ " . وَقَالَ رَسُولُ اللَّهِ ﷺ "
إِنَّمَا جُعِلَ الإِذْنُ مِنْ أَجْلِ الْبَصَرِ " .