Genesis 48:19

But his father was not willing, and said, I know, my son, I know that he is the firstborn, and also that he will be a great people, and will also be multiplied; yet will his younger brother be greater than he, and his sons be greater among the nations.

ואולם, “but, however.”

יהיה לעם, will become so numerous until people will refer to his descendants as “a nation.”

וגם הוא יגדל, he will also develop into becoming very numerous. However his younger brother will become even more numerous. At the Exodus from Egyptian the arms-bearing males of the tribe of Ephrayim were 45.500 (Numbers 1,33-35 as opposed to only 32.200 members of the tribe of Menashe. Interestingly, when numbering the males over 20 who entered the Holy Land, the members of the tribe of Menashe outnumbered those of Ephrayim by 52.700 to 32.500. (Numbers 26,34-36.) If we keep this in mind we may have to redefine the meaning of the word יגדל when used by Yaakov not as referring to numerical strength, but as referring to the great men produced by each of these tribes and the relative importance of these men. We know that Moses’ successor, Joshua, was from the tribe of Ephrayim. He was a great saviour, and conquered the land of Canaan enabling the promise of G’d to the patriarchs to finally become realised. The tribe of Ephrayim also provided the first king of the 10 tribes who had split away from Solomon’s son Rechavam after the death of Solomon. Furthermore, throughout the history of the Jewish people until the destruction of the first Temple the political rivalry between Ephrayim and Yehudah is well documented, whereas hardly ever is Menashe mentioned as playing a major part in this. When the prophet Isaiah prophesied an idyllic future, he described this as being characterised by the end of the rivalry between Ephrayim and Yehudah. (Isaiah 11,13). Still, it is possible to also understand the word יגדל ממנו as referring to numerical strength, as except in the single instance we mentioned before Ephrayim always outnumbered Menashe. We must also take into consideration the words וזרעו יהיה מלא הגויים, “and his seed will become plentiful enough to form nations.” The unique phenomenon of the members of Ephrayim being inferior in numbers at the time the Israelites entered the Holy Land may possibly be accounted for by the tradition that 30 years prior to the Exodus the tribe of Ephrayim rebelled, left Egypt and marched to the land of the Philistines on the way to the land of Canaan. According to that report they lost 200.000 of their number in a battle at Gat. [the reason why I do not think this relevant is that if so, there should have been fewer member of the tribe of Ephrayim at the time of the Exodus, instead of 40 years later when near entering the Holy Land. Ed.]