'Knees' in the Bible

All hands will hang limp and all knees will become like water.

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

Again he measured a thousand and led me through the water, water reaching the knees. Again he measured a thousand and led me through the water, water reaching the loins.