Midrash sur La Genèse 38:30

Another interpretation (of Gen. 39:1): WHEN JOSEPH WAS TAKEN DOWN TO EGYPT…. What is written above on the matter (in Gen. 38:29)? AND IT CAME TO PASS THAT, AS HE DREW BACK HIS HAND < … > [SO HIS NAME WAS CALLED PEREZ]. Here is kingship (according to Ruth 4:18): THESE ARE THE GENERATIONS OF PEREZ.⁶⁸The biblical text continues with a genealogy from Perez to David. (Gen. 38:30:) THEN AFTERWARDS HIS BROTHER CAME OUT. Here is a priest. Then afterwards (in Gen. 39:1): WHEN JOSEPH WAS TAKEN DOWN TO EGYPT, the Holy One simply brought them the good news that, wherever they went, they would have the services of a king and a priest. How so? In Egypt < they had > a king and a priest, as stated (in Exod. 7:8): NOW THE LORD SAID UNTO MOSES AND UNTO AARON…. Also in their Exodus < they had a king and a priest > (according to Ps. 77:21 [20]): YOU LED YOUR PEOPLE LIKE A FLOCK BY THE HAND OF MOSES AND AARON.