The angel that redeemed me from all evil will bless these lads. They will be called by my name and the names of my fathers Avraham and Yitzchak. They will multiply in the land. (Beresheit 48:16)
1. The basic components of Yaakov’s address.
Yaakov and his family have descended to Egypt. Yosef rules the country and provides sustenance for his father, his brothers, and their households. Yaakov becomes ill. Yosef and his two sons – Ephraim and Menashe – visit Yaakov. Yaakov addresses Yosef. He begins with a review of the pledges that Hashem had made to him. Then, he tells Yosef that Ephraim and Menashe will merit a special role in Bnai Yisrael. They will be treated as direct sons of Yaakov. They will have the same status, within Bnai Yisrael, as Reuven and Shimon. In short, there are two parts to this portion of Yaakov’s comments. He begins with an introduction, reviewing the promises Hashem had made to him. He then bestows his own blessings upon Yosef and his sons.
In order to understand this portion of Yaakov’s address, it is necessary to interpret his introduction, the blessings he bestowed, and the relationship between these two elements. This process will begin with consideration of the basic meaning of blessing Yaakov granted. Understanding this blessing requires a brief introduction.
2. The meaning of Yaakov’s blessing: Conferring upon Ephraim and Menashe the status of Shevatim.
Yaakov had twelve sons. These sons were the progenitors of the Shevatim – the Tribes of Israel. Each was the founder or the patriarch of a separate tribe. Their descendants were members of the tribe of their patriarch. These descendants could not establish new Shevatim. According to this principle, Yosef's two sons should have been members of the Tribe of Yosef. It should have been impossible for Ephraim and Menashe to be the patriarchs of their own tribes. They are Yosef's children, not the sons of Yaakov.
Now, Yaakov’s basic message to Yosef can be understood. He told Yosef that Ephraim and Menashe will be regarded as sons of Yaakov. They will be elevated to the level of Reuven and Shimon. There will not be a Tribe of Yosef. Instead, Yosef will be the progenitor of two of the Shevatim – Ephraim and Menashe.
3. Yaakov promised that his name and those of the forefathers will be associated with Ephraim and Menashe.
However, there is another element to Yaakov’s blessing. In closing his address, Yaakov says that Ephraim and Menashe will be called by his name and the names of his fathers Avraham and Yitzchak. The meaning of this statement is not clear. Nachmanides offers an explanation. Avraham, Yitzchak, and Yaakov will always be identified with the descendants of Ephraim and Menashe. In other words, the forefathers will always be remembered through the offspring of Ephraim and Menashe. Nachmanides explains that this promise has far-reaching consequences. It implies that the offspring of Ephraim and Menashe will never be lost or destroyed. Some remnant will always remain. This remnant is the fulfillment of Yaakov's promise. Some remnant must always survive because through this remnant the forefathers are identified with the descendants of Ephraim and Menashe. In short, this second element of Yaakov’s blessing was a guarantee that the progeny of Ephraim and Menashe would survive all challenges and tragedies that would befall Bnai Yisrael. Nachmanides’ comments require closer scrutiny. What is the basis for his interpretation?
4. Yaakov’s blessing can only be understood in the context of the pledges he received from Hashem.
Nachmanides’ comments can be understood in the context of the first portion of Yaakov’s address – his introduction. In this preamble, Yaakov reviewed the pledges that Hashem had made to him. He explained that Hashem had appeared to him at Luz. There, Hashem made three pledges to Yaakov. First, He told Yaakov that He would have many descendants. Second, Hashem promised that Yaakov’s children would be a congregation of nations. Third, He told Yaakov that his descendants would possess the Land of Israel. Apparently, these pledges establish the context for the blessing that Yaakov bestowed upon Ephraim and Menashe. However, the relevance of this context to the blessings must be explained.
5. Bnai Yisrael is an Assembly of Shevatim.
In order to understand the relevance of these pledges and their role in establishing the context of Yaakov’s blessings, the meaning of the pledges must be clearly understood. The meaning of the first promise is clear. Yaakov will have many descendants. The last pledge is also easily understood. Hashem promises Yaakov that his descendants will possess the Land of Israel. However, the second promise is less easily interpreted. What is a “congregation of nations”? Unkelus explains this phrase. He translates it as “an Assembly of Shevatim.” Bnai Yisrael will be composed of individual Shevatim. Through communicating this to Yaakov as a pledge, Hashem indicated to him that the structure of Bnai Yisrael as an assembly of individual Shevatim is not merely a practical, political, or administrative measure. The structure of the nation as an assemblage of Shevatim is an expression of the fundamental structure of the nation. In other words, Bnai Yisrael is not composed of individual tribes in order to facilitate the governance of the nation or as a consequence of political forces that prevented the individual tribes from fully integrating. The existence of the Shevatim within the nation is an expression of the nation’s design as decreed by Hashem. In future generations, as the nation grew, these Shevatim did emerge as Hashem promised. Their emergence was the fulfillment of Hashem’s promise to Yaakov. Furthermore, this system of shevatim is a permanent fixture of Bnai Ysrael.
Now, we can begin to appreciate the relevance of Yaakov’s introduction. Yaakov elevated Ephraim and Menashe to the level of his own children. They would each establish a separate tribe. Yaakov introduced this blessing through explaining the source for the system of Shevatim. He tells Yosef, that the institution of Shevatim was established by Hashem. It is an expression of the nation’s basic design. The formation of the Tribe of Ephraim and the Tribe of Menashe will represent the fulfillment of Hashem’s promise; Bnai Yisrael will be an Assembly of Tribes.
6. The survival of Ephraim’s and Menashe’s descendants is directly related to their status as Shevatim.
Rav Yitzchak Zev Soloveitchik Zt”l suggests that Hashem’s promise to create a system of Shevatim is the basis for Nachmanides’ interpretation of Yaakov’s blessing. Yaakov had promised Yosef that Ephraim and Menashe would be the forerunners of Shevatim. Implicit in this promise was the second element of Yaakov’s blessing – the guarantee that their descendants would survive throughout the generations. How is this guarantee implied?
Rav Soloveitchik explains that there are two aspects to Hashem’s promise to create an Assembly of Shevatim. First, as explained above, the institution of Shevatim is a permanent element of Bnai Yisrael. The nation will always be composed of individual Shevatim. Second, each Shevet is a permanent element of the nation. No tribe can be destroyed or cease to exist. On this basis, Yaakov made two pledges to Yosef. First, he promised Yosef that Ephraim and Menashe will be the forerunners of Shevatim. Second, no tribe can ever cease to exist. Therefore, the survival of Ephraim and Menashe’s descendants is implicit in this blessing and assured.
 Rabbaynu Moshe ben Nachman (Ramban / Nachmanides), Commentary on Sefer Beresheit 48:16.
 Targum Unkelus, Sefer Beresheit 48:4.
 Mesechet Baba Batra 115b.
 Rav Yitzchak Zev Soloveitchik, Chidushai MaRan RIZ HaLeyve on the Torah, Parshat VaYeche.