darken someone's door

Probably from the observation that one's shadow falling upon a door whilst standing at it causes it to appear darkened. Alternatively, possibly derived from an old sense of darken meaning "to lie in wait, loiter, lurk".

• ""I'll tell you, Peter," said I, "were I my lord, and a friend or kinsman of mine should leave the town while the court was sitting, that kinsman, or be he what he liked, should never darken my door again.""
• "He promised the poor His heaven, He loved and lived with the poor; He said that the rich man's shadow Should never darken His door."
• "[T]he squire ain't sociable an' the neighbors never darken his door."
• "Luckily, I'd scored some good-paying clients in the past two months along with the usual losers who darken my door and waste my time."