Genesis 48:19-20

19But his father refused. “I know, my son; I know,” he replied. “Manasseh will also become a great people, but his younger brother will become even greater. And his descendants will become a multitude of nations.”

20So Jacob blessed the boys that day with this blessing: “The people of Israel will use your names when they give a blessing. They will say, ‘May God make you as prosperous as Ephraim and Manasseh.’” In this way, Jacob put Ephraim ahead of Manasseh.