Commentary for Genesis 9:27

יפת אלהים ליפת MAY GOD ENLARGE JAPHETH — The Targum renders the verb by יפתי meaning, “may He extend”.

באהלי שם, (the plural mode) is a reference to Torah academies in addition to the Temple.

יפת אלוקים, this expression is appropriately translated as “may He expand,” the root of the word יפת being פתח, an opening. It is in the transitive mode, as for instance Isaiah 41,2 ומלכים ירד, from the root רדה “to rule.” Noach prays that Yaphet’s share of the earth will be enlarged. Even though Noach promises quantity to Yaphet, he reserves quality for Shem, saying that G’d will make His home in the portion of the earth allocated to Shem’s descendants. (see Exodus 29,45) Moses also specifically prays for a renewal of this blessing after the sin of the golden calf in Exodus 33,16) when he pleads for the Jewish people to enjoy this distinction.