Sahl ibn Sa'd told him that a man looked from a room through the door of the Prophet ﷺ while the Prophet ﷺ had a comb with which he was scratching his hair. When the Prophet ﷺ saw him, he said, "If I had known that you were looking at me, I would have stabbed you in the eye with this!"

حَدَّثَنَا عَبْدُ اللهِ بْنُ صَالِحٍ، قَالَ: حَدَّثَنَا اللَّيْثُ قَالَ: حَدَّثَنِي ابْنُ شِهَابٍ، أَنَّ سَهْلَ بْنَ سَعْدٍ أَخْبَرَهُ، أَنَّ رَجُلاً اطَّلَعَ مِنْ جُحْرٍ فِي بَابِ النَّبِيِّ ﷺ، وَمَعَ النَّبِيِّ ﷺ مِدْرًى يَحُكُّ بِهِ رَأْسَهُ، فَلَمَّا رَآهُ النَّبِيُّ ﷺ قَالَ: لَوْ أَعْلَمُ أَنَّكَ تَنْتَظِرُنِي لَطَعَنْتُ بِهِ فِي عَيْنِكَ.