And Israel beheld Joseph's sons, and said, Who are these?
9 And Joseph said unto his father, They are my sons, whom God hath given me in this place. And he said, Bring them, I pray thee, unto me, and I will bless them.
10 Now the eyes of Israel were dim for age, so that he could not see. And he brought them near unto him; and he kissed them, and embraced them.
11 And Israel said unto Joseph, I had not thought to see thy face: and, lo, God hath shewed me also thy seed.
12 And Joseph brought them out from between his knees, and he bowed himself with his face to the earth.
13 And Joseph took them both, Ephraim in his right hand toward Israel's left hand, and Manasseh in his left hand toward Israel's right hand, and brought them near unto him.
14 And Israel stretched out his right hand, and laid it upon Ephraim's head, who was the younger, and his left hand upon Manasseh's head, guiding his hands wittingly; for Manasseh was the firstborn.
15 And he blessed Joseph, and said, God, before whom my fathers Abraham and Isaac did walk, the God which fed me all my life long unto this day,
16 The Angel which redeemed me from all evil, bless the lads; and let my name be named on them, and the name of my fathers Abraham and Isaac; and let them grow into a multitude in the midst of the earth.
17 And when Joseph saw that his father laid his right hand upon the head of Ephraim, it displeased him: and he held up his father's hand, to remove it from Ephraim's head unto Manasseh's head.
18 And Joseph said unto his father, Not so, my father: for this is the firstborn; put thy right hand upon his head.
19 And his father refused, and said, I know it, my son, I know it: he also shall become a people, and he also shall be great: but truly his younger brother shall be greater than he, and his seed shall become a multitude of nations.
20 And he blessed them that day, saying, In thee shall Israel bless, saying, God make thee as Ephraim and as Manasseh: and he set Ephraim before Manasseh.
21 And Israel said unto Joseph, Behold, I die: but God shall be with you, and bring you again unto the land of your fathers.
22 Moreover I have given to thee one portion above thy brethren, which I took out of the hand of the Amorite with my sword and with my bow.
Joseph who is separated from his brothers and sold into slavery, hidden among the Gentiles, marries a Gentile wife and brings his Gentile sons before his father for the birthright blessing.
Joseph received a double portion through Ephraim and Manasseh, and it is through them that the Gentiles are brought in.
his seed shall become a multitude of nations
מלו מלוא מלא
melô' melô' melô
mel-o', mel-o', mel-o'
From H4390; fulness (literally or figuratively): - X all along, X all that is (there-) in, fill, (X that whereof . . . was) full, fulness, [hand-] full, multitude.
Apparently from the same root as H1465 (in the sense of massing); a foreign nation; hence a Gentile; also (figuratively) a troop of animals, or a flight of locusts: - Gentile, heathen, nation, people.
The birthright blessing passed through Ephraim, the prince of the lost house of Israel, his seed shall become a multitude of nations, is the fulness [melô] of the Gentiles [goy].