'Knees' in the Bible

And she said, Behold my maid Bilhah, go in unto her; and she shall bear upon my knees, that I may also have children by her.

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

And Joseph saw Ephraim's children of the third generation: the children also of Machir the son of Manasseh were brought up upon Joseph's knees.