Ezekiel 26:3

³ Therefore, thus said the Lord Jehovah: Lo, I [am] against thee, O Tyre, And have caused to come up against thee many nations, As the sea causeth its billows to come up.

Knock

'Behold I stand at the door and knock,' as in Revelation 3:20, signifies the perpetual presence and workings of the Lord with man.