Charles Ellicott Commentary Genesis 48:20

"And he blessed them that day, saying, In thee will Israel bless, saying, God make thee as Ephraim and as Manasseh: and he set Ephraim before Manasseh." — Genesis 48:20 (ASV)

In thee shall Israel bless. —In conformity with these words, the Israelites to this day use Jacob’s formula in blessing their children.