If a person were to cast a glance in your (house) without permission, and you had in your hand a staff and you would have thrust that in his eyes, there is no harm for you.
أَنَّ رَسُولَ اللَّهِ ﷺ قَالَ لَوْ أَنَّ رَجُلاً اطَّلَعَ عَلَيْكَ بِغَيْرِ إِذْنٍ فَخَذَفْتَهُ بِحَصَاةٍ فَفَقَأْتَ عَيْنَهُ مَا كَانَ عَلَيْكَ مِنْ جُنَاحٍ