Luke 11:7

And he from within shall answer and say, Trouble me not: the door is now shut, and my children are with me in bed; I cannot rise and give thee.

Cross-reference

Luke 13:25 also describes a shut door and knocking—there it's about final exclusion, echoing the same imagery.

Matthew 25:10 also features a shut door after a point of no return—similar image of a closed door preventing entry.