Mishkat al-Masabih 16 Retaliation كتاب القصاص 61

وَعَنْهُ أَنَّهُ سَمِعَ رَسُولَ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ يَقُولُ: «لَوِ اطَّلَعَ فِي بَيْتِكَ أحدٌ ولمْ تَأذن لَهُ فخذفته بحصاة ففتأت عَيْنَهُ مَا كَانَ عَلَيْكَ مِنْ جُنَاحٍ»

He told that he heard God’s Messenger say, “If anyone were to look into your house without receiving your permission and you were to throw a pebble at him and put out his eye, you would be guilty of no offence.” (Bukhari and Muslim)