Efraim and Menashe

Shavua Tov. A question that is asked related to today's Parsha is why do we bless our daughters that they should be like Sara, Rivka, Rachel, and Leah, but we bless the boys that they should be like Efraim and Menashe? Why not be consistent and bless our sons that they should be like Avraham, Yitzchak, and Yaakov?

We must remember that Egypt was the place of the greatest impurity in the world. The Rambam says that it was so impure that men married men and women married women. So we bless our sons that wherever they travel in the world, and whatever temptations they might be faced with, they should be like Efraim and Menashe. Yosef's two sons managed to keep themselves strong in a very difficult situation. We bless our sons that they be equally strong.