'Knocks' in the Bible

For it is always he who asks that receives, he who seeks that finds, and he who knocks that has the door opened to him.

For every one who asks, receives; and he who seeks, finds; and to him who knocks, the door shall be opened.

and be yourselves like men waiting for their master--on the look-out till he shall return from the wedding feast--that, when he comes and knocks, they may open the door instantly.