Midrasch zu Bereschit 47:21

Another interpretation (of Gen. 39:1): WHEN JOSEPH WAS TAKEN DOWN < TO EGYPT, POTIPHAR … BOUGHT HIM >. What is the meaning of WHEN JOSEPH WAS TAKEN DOWN? That he moved the Egyptians from place to place. < It is > just as you say (in Gen. 47:21): HE REMOVED THE PEOPLE BY CITIES < FROM ONE END OF EGYPT'S BORDER TO THE OTHER >. Thus he was taking them up from here and putting them there so that they would not taunt the Israelites by calling them exiles < and > children of exiles.⁴⁸Hul. 60b; Targum Pseudo-Jonathan, Gen. 47:21; Frag. (Jerusalem) Targum, Gen. 47:21.