Knock - Vine's Expository Dictionary of New Testament Words
Knock[ 1,,G2925, krouo ]
to strike, knock," is used in the NT of "knocking" at a door,
(a) literally, Luke 12:36; Acts 12:13, Acts 12:16;
(b) figuratively, Matthew 7:7-Matthew 7:8; Luke 11:9-Luke 11:10 (of importunity in dealing with God); Luke 13:25; Revelation 3:20.