21:17 Rather, he must acknowledge the son of the less loved34 wife as firstborn and give him the double portion35 of all he has, for that son is the beginning of his father’s procreative power36—to him should go the right of the firstborn.
tnHeb “measure of two.” The Hebrew expression פִּי שְׁנַיִם (piy shénayim) 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).
36
tnHeb “his generative power” (אוֹן, ’on; cf. HALOT22s.v.). Cf. NAB “the first fruits of his manhood”; NRSV “the first issue of his virility.”