Genesis 48:18

18 He said to his father, "Not that way, father. This is the older boy; put your right hand on 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 May the angel, who has rescued me from all harm, bless them! May my name and the name of my fathers Abraham and Isaac live on through these boys! May they have many children, many descendants!"
17 Joseph was upset when he saw that his father had put his right hand on Ephraim's head; so he took his father's hand to move it from Ephraim's head to the head of Manasseh.
18 He said to his father, "Not that way, father. This is the older boy; put your right hand on his head."
19 His father refused, saying, "I know, son, I know. Manasseh's descendants will also become a great people. But his younger brother will be greater than he, and his descendants will become great nations."
20 So he blessed them that day, saying, "The Israelites will use your names when they pronounce blessings. They will say, "May God make you like Ephraim and Manasseh.' " In this way Jacob put Ephraim before Manasseh.
Scripture taken from the Good News Translation - Second Edition, Copyright 1992 by American Bible Society. Used by Permission.