that the Messenger of Allah (ﷺ) said: Whoever lifts the curtain so that his sight enters the house before he was given permission, and he seeks the nakedness of its inhabitants, then he has done something punishable which was not lawful for him to do. If it were that when he gazed into it, he was facing a man who lanced his eyes, there would be nothing wrong with him doing so. But if a man passes by a door that has no cover over it, and it is not closed and he looks, then there is no sin on him, the sin is only on the inhabitants of the house.

that the Prophet (ﷺ) was in his house when a man looked in at him, so he lunged towards him with an arrow head, so the man backed up.

that a man peeked in on the Messenger of Allah (ﷺ), in one of the apartments of the Prophet (ﷺ), while the Prophet (ﷺ) had a Midrah (an iron comb) with which he was scratching his head. So the Prophet (ﷺ) said: If I knew that you were looking then I would have poked your eyes with it. Seeking permission has only been enjoined because of the sight.