'Knees' in the Bible

And it was so, that, when Solomon had made an end of praying all this prayer and supplication unto Jehovah, he arose from before the altar of Jehovah, from kneeling on his knees with his hands spread forth toward heaven.

So Ahab went up to eat and to drink. And Elijah went up to the top of Carmel; and he bowed himself down upon the earth, and put his face between his knees.

Yet will I leave me'seven thousand in Israel, all the knees which have not bowed unto Baal, and every mouth which hath not kissed him.