'Knocking' in the Bible

“Ask and keep on asking and it will be given to you; seek and keep on seeking and you will find; knock and keep on knocking and the door will be opened to you.

For everyone who keeps on asking receives, and he who keeps on seeking finds, and to him who keeps on knocking, it will be opened.

“So I say to you, ask and keep on asking, and it will be given to you; seek and keep on seeking, and you will find; knock and keep on knocking, and the door will be opened to you.

For everyone who keeps on asking [persistently], receives; and he who keeps on seeking [persistently], finds; and to him who keeps on knocking [persistently], the door will be opened.

But [meanwhile] Peter continued knocking; and when they opened the door and saw him, they were completely amazed.