וַיְבָ֨רֲכֵ֜ם בַּיּ֣וֹם הַהוּא֮ לֵאמוֹר֒ בְּךָ֗ יְבָרֵ֤ךְ יִשְׂרָאֵל֙ לֵאמֹ֔ר יְשִֽׂמְךָ֣ אֱלֹהִ֔ים כְּאֶפְרַ֖יִם וְכִמְנַשֶּׁ֑ה וַיָּ֥שֶׂם אֶת־אֶפְרַ֖יִם לִפְנֵ֥י מְנַשֶּֽׁה׃
Und er segnete sie an jenem Tage und sprach: Mit dir wird Israel seine Kinder segnen und also sprechen: Gott lasse dich werden wie Ephraim und Manasse!« So stellte er Ephraim vor Manasse.
Rashi on Genesis
בך יברך ישראל IN THEE SHALL ISRAEL BLESS — When one wishes to bless his sons he will bless them by reciting the formula with which they were blessed — a man will say to his son, “God make thee as Ephraim and as Manasseh.”
Ramban on Genesis
AND HE BLESSED THEM THAT DAY. The meaning of that day is that since Joseph had urged him to give Menasheh precedence, the verse declares that Jacob did not wish to remove his right hand from Ephraim’s head to that of Menasheh. Moreover, he expressly reiterated on that occasion, in Joseph’s presence, when he blessed them by saying, As Ephraim and Menasheh. And he put Ephraim before Menasheh in all his blessings.
Rashbam on Genesis
בך יברך ישראל, each Israelite his respective son.