Bereshis 48:18

18 And Yosef said unto aviv, Not so, Avi; for this is the bechor; put thy yamin upon his rosh.

Bereshis 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.

Bereshis 48:18 In-Context

16 The Malach which redeemed me from kol rah, may he make a brocha on the ne’arim, and let my shem be named on them, and the shem of my Avot Avraham and Yitzchak; and let them grow into a multitude in the midst of ha’aretz.

17 And when Yosef saw that aviv laid his yamin upon the rosh Ephrayim, it displeased him; and he took hold of yad aviv, to remove it from rosh Ephrayim unto rosh Menasheh.

18 And Yosef said unto aviv, Not so, Avi; for this is the bechor; put thy yamin upon his rosh.

19 And aviv refused, and said, I know it, beni (my son), I know it; he also shall become a people, and he also shall be great; but truly achiv hakaton shall be greater than he, and his zera shall become a multitude of Goyim.

20 And he made a brocha on them that day, saying, In thee shall Yisroel bless, saying, Elohim make thee like Ephrayim and like Menasheh; and he set Ephrayim before Menasheh.