Is it permissible to strike an intruder who looks and then leaves?
General Chapter
Al-Mughni
Book of Beverages (Intoxicants)
Primary text
It is not permissible to strike the intruder if they look and then depart, because the Prophet (peace be upon him) did not strike the one who looked and then left. Abandoning the injurious act is analogous to someone biting and then ceasing the bite; in the latter case, pulling out their teeth is impermissible.
Supporting text
This ruling applies whether the opening was small, like a pinhole, or large. Some scholars extend this ruling to an open door, although the preferred view is that striking someone looking through an open door is impermissible because the negligence lies with the owner who left the door open, implying the owner should exercise caution and expect observation.