'Knees' in the Bible

Now a leper came to him and fell to his knees, asking for help. "If you are willing, you can make me clean," he said.

Now as Jesus was starting out on his way, someone ran up to him, fell on his knees, and said, "Good teacher, what must I do to inherit eternal life?"

But when Simon Peter saw it, he fell down at Jesus' knees, saying, "Go away from me, Lord, for I am a sinful man!"

Then he fell to his knees and cried out with a loud voice, "Lord, do not hold this sin against them!" When he had said this, he died.

Therefore, strengthen your listless hands and your weak knees,