Ulangan 33:17

33:17 May the firstborn of his bull bring him honor,

and may his horns be those of a wild ox;

with them may he gore all peoples,

all the far reaches of the earth.

They are the ten thousands of Ephraim, ¹ 

and they are the thousands of Manasseh.

[33:17]  ¹ sn Ephraim and Manasseh were the sons of Joseph who became founders of the two tribes into which Joseph’s descendants were split (Gen 48:19-20). Jacob’s blessing granted favored status to Ephraim; this is probably why Ephraim is viewed here as more numerous than Manasseh.