At best, Ephraim and Menasheh are considered equal to Reuven and Shimon, two of the Shivtei Kah, Tribes. However, when fathers and mothers bless their children they do not bless them, “May you be like Reuven and Shimon” (or any of the other Shevatim). Why, then, do Ephraim and Menasheh serve as paradigms for blessing? Surely, they were not better people than Reuven and Shimon. Sefas Emes explains the distinction. Although Ephraim and Menasheh were “second generation,” and therefore at birth were not on the same spiritual plateau as the Shevatim, they achieved their elevated status by developing themselves to reach Shevatim status. In other words, while it is true that they did not have a higher status than the Shevatim, they developed themselves to equal them. Considering that Menasheh and Ephraim started out light years behind Reuven and Shimon, achieving Shevatim status was an exceptional feat. This is the blessing of spiritual growth which every parent gives his children: “May you be like Ephraim and Menasheh – in other words, “May you grow spiritually from strength to strength.”
The Sefas Emes is teaching us that we have “natural” strengths – physical attributes with which we are born and upon which our natural potential is established. A human being born with these physical qualities is capable of achieving just so much. Then he has the spiritual ability to transcend this potential by pushing harder, working more, exerting himself so that he makes an impact. Hashem listens and grants him the ability, the strength, the wisdom to develop further, deeper, higher. This is the blessing of Yesimcha Elokim k’Ephraim u’k’Menasheh: You should not be impeded by arbitrary boundaries. Just as Ephraim and Menasheh superseded their physical capabilities and achieved Shevet status, so can you. Just as they did it on their own through exceptional motivation and work, so must you. You do yours – Hashem will do the rest.
