'Knees' in the Bible

All hands will hang limp and all knees will be as weak as water.

And when they say to you, ‘Why do you sigh and groan?’ you shall answer, ‘Because of the news that is coming; and every heart will melt and all hands will be frail, and every spirit will faint and all knees will be weak as water. Behold, it comes and it will happen,’ says the Lord God.”

Again he measured a thousand [cubits] and led me through the water, water that was knee-deep. Again he measured a thousand [cubits] and led me through the water, water reaching the hips.