'Knees' in the Bible

And she said, Behold, there is my maid, Bilhah: go in to her, in order that she may bear on my knees, and I may also be built up by her.

And Joseph brought them out from his knees, and bowed down with his face to the earth.

And Joseph saw Ephraim's children of the third generation; the sons also of Machir the son of Manasseh were born on Joseph's knees.