Sahih Muslim , Book 25, Hadith 5370 (USC-MSA) ⓘ
Abu Huraira reported having heard Allah's Messenger say: He who peeped into the house of people without their consent, it is permissible for them to put out his eyes.
حَدَّثَنِي زُهَيْرُ بْنُ حَرْبٍ، حَدَّثَنَا جَرِيرٌ، عَنْ سُهَيْلٍ، عَنْ أَبِيهِ، عَنْ أَبِي هُرَيْرَةَ، عَنِ النَّبِيِّ صلى الله عليه وسلم قَالَ " مَنِ اطَّلَعَ فِي بَيْتِ قَوْمٍ بِغَيْرِ إِذْنِهِمْ فَقَدْ حَلَّ لَهُمْ أَنْ يَفْقَئُوا عَيْنَهُ " .
also referenced under: Book 38, Hadith 57 (In-Book) & Hadith 2158 (Reference)