Genesis 48:18

18 And Joseph said to his father, "Not so, my father; because this one [is] the firstborn. Put your right [hand] upon his head."

Genesis 48:18 Meaning and Commentary

Genesis 48:18

And Joseph said unto his father, not so, my father
It is not right, it should not so be, that the right hand should be put on the youngest, and the left hand on the eldest; for this [is] the firstborn;
directing him to Manasseh, and seeking to guide his hand towards him: put thy right hand upon his head;
Joseph was for proceeding according to the order of birthright, but Jacob was directed by a spirit of prophecy, as follows.

Genesis 48:18 In-Context

16 The angel who redeemed me from all evil, may he bless the boys. And through them let my name be perpetuated, and the name of my fathers, Abraham and Isaac. And let them multiply into many in the midst of the earth.

17 When Joseph saw that his father put his right hand on the head of Ephraim, he was displeased. And he took hold of his father's hand to remove it from the head of Ephraim [over] to the head of Manasseh.

18 And Joseph said to his father, "Not so, my father; because this one [is] the firstborn. Put your right [hand] upon his head."

19 But his father refused and said, "I know, my son; I know. He also shall become a people, and he also shall be great, but his younger brother shall be greater than him, and his offspring shall become a multitude of nations."

20 So he blessed them that day, saying, Through you Israel shall pronounce blessing, saying, 'May God make you like Ephraim and like Manasseh.'" So he put Ephraim before Manasseh.