Deuteronomy 21:17

21:17 Rather, he must acknowledge the son of the less loved ¹  wife as firstborn and give him the double portion ²  of all he has, for that son is the beginning of his father’s procreative power ³  – to him should go the right of the firstborn.

Deuteronomy 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, ⁴ 

and they are the thousands of Manasseh.

[21:17]  ¹ tn See note on the word “other” in v. 15.

[21:17]  ² tn Heb “measure of two.” The Hebrew expression פִּי שְׁנַיִם (piy shÿnayim) suggests a two-thirds split; that is, the elder gets two parts and the younger one part. Cf. 2 Kgs 2:9; Zech 13:8. The practice is implicit in Isaac’s blessing of Jacob (Gen 25:31-34) and Jacob’s blessing of Ephraim (Gen 48:8-22).

[21:17]  ³ tn Heb “his generative power” (אוֹן, ’on; cf. HALOT 22 s.v.). Cf. NAB “the first fruits of his manhood”; NRSV “the first issue of his virility.”

[33:17]  ⁴ 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.