Genesis 21:12 - Exposition

And God said unto Abraham ,—probably in a dream, or night vision ( vide Genesis 21:14 )— Let it not be grievous in thy sight because of the lad, and because of thy bondwoman ;—who was never recognized by God as Abraham's wife (cf. Genesis 16:8 )— in all that Sarah hath said unto thee, hearken unto her voice. Though Sarah's counsel was approved by God, it does not follow that her conduct was. On a former occasion Abraham's hearkening unto Sarah's voice had led to sin ( Genesis 16:2 ); this time it would lie exactly in the line of duty. For in Isaac shall thy seed be called. Literally, in Isaac shall seed ( i.e. posterity) be called to thee ; meaning neither, " by Isaac shall thy seed be called, or named" (Hofmann, Kalisch, Ainsworth), nor, "in Isaac shall thy seed be called into existence" (Dreschler); but, "in Isaac shall there be posterity to thee which shall pass as such," i.e. be called or recognized as such (Keil); or, more simply, "in Isaac," i.e. in the line of Isaac, "shall be called to thee a seed," i.e. a seed par excellence, the seed already promised (Bleek, Delitzsch, Rosenmüller, Alford, Murphy).