ADAM WAS GIVEN THE BIRTHRIGHT

Midrash Rabbah - Genesis 97:6

AND ISRAEL SAID UNTO JOSEPH: BEHOLD I DIE etc. (Genesis 48:21) … MOREOVER I HAVE GIVEN TO THEE ONE PORTION (SHECHEM) ABOVE THY BRETHREN (Genesis 48:22)

… R. Judah maintained: The PORTION (SHECHEM) means the birthright and the raiment of Adam.