'Knees' in the Bible

And she saith, 'Lo, my handmaid Bilhah, go in unto her, and she doth bear on my knees, and I am built up, even I, from her;'

And Joseph bringeth them out from between his knees, and boweth himself on his face to the earth;

and Joseph looketh on Ephraim's sons of the third generation; sons also of Machir, son of Manasseh, have been born on the knees of Joseph.