(495) بَابُ الاسْتِئْذَانُ مِنْ أَجْلِ النَّظَرِ
Sahl ibn Sa'd told him that a man looked from a room through thedoor of the Prophet, may Allah bless him and grant him peace, while theProphet, may Allah bless him and grant him peace, had a comb with whichhe was scratching his hair. When the Prophet, may Allah bless him and granthim peace, saw him, he said, "If I had known that you were looking at me,I would have stabbed you in the eye with this!"
Reference: Al-Adab Al-Mufrad 1070
In-book reference: Book 43, Hadith 20
English translation: Book 43, Hadith 1070