'Knock' in the Bible

"So I say to you, 'Ask, and what you ask for shall be given to you; seek, and you shall find; knock, and the door shall be opened to you.'

As soon as the Master of the house shall have risen and shut the door, and you have begun to stand outside and knock at the door and say, "'Sir, open the door for us' --"'I do not know you,' He answers; 'you are no friends of mine.'