The Book of Manners and Etiquette
Ṣaḥīḥ Muslim 5642
مَنِ اطَّلَعَ فِي بَيْتِ قَوْمٍ بِغَيْرِ إِذْنِهِمْ فَقَدْ حَلَّ لَهُمْ أَنْ يَفْقَئُوا عَيْنَهُ
mani āṭṭalaʿa fī bayti qawmin bighayri idhnihim faqad ḥalla lahum an yafqaʾūā ʿaynah
Transliteration generated from the Arabic vowel marks
The full narration
Abu Huraira reported having heard Allah's Messenger (ﷺ) say:He who peeped into the house of people without their consent, it is permissible for them to put out his eyes
Source
Ṣaḥīḥ Muslim · 5642
Ṣaḥīḥ