פירוש על במדבר 26:39

לשפופם OF SHEFUFAM - he was identical with Muppim, but was so called also after Joseph because Joseph became enfeebled (שפוף) through his sufferings among the nations.

Being humbled among the nations. שפוף ["humble"] has the connotation of hovering [just above the ground].

לשפופם, he is identical with מופים, in Genesis 46,21.