'Knees' in the Bible

When Solomon had finished praying this entire prayer and supplication to the Lord, he arose from before the altar of the Lord, from kneeling on his knees with his hands spread toward heaven.

So Ahab went up to eat and drink. But Elijah went up to the top of Carmel; and he crouched down on the earth and put his face between his knees.

Yet I will leave 7,000 in Israel, all the knees that have not bowed to Baal and every mouth that has not kissed him.”