Sforno on Genesis 48:6/ספורנו על בראשית מ״ח:ו׳

1ומולדתך אשר הולדת אחריהם, your grandchildren, who are truly called מולדתך, seeing that this expression includes children and grandchildren,לך יהיו, they will be known as part of בית יוסף, the house of Joseph, bearing your name. And their blessing will be part of your blessing, not separate blessings.על שם אחיהם יקראו בנחלתם, everyone of Menashe’s sons will also incorporate the name of his father Menashe, as will the sons of his brother, who will also incorporate the name of their father Ephrayim as part of their individual names. They were to inherit part of the land of Israel together with Yaakov’s other sons.