eipe de o qeoV tw Abraam, mh sklhron estw enantion sou peri tou paidiou, kai peri thV paidiskhV:  panta osa an eiph soi Sarra, akoue thV fwnhV authV oti 
en Isaak klhqhsetai soi sperma
 

oud oti eisin sperma Abraam panteV tekna, all : 
en Isaak klhqhsetia soi sperma

proV on elalhqh oti 
en Isaak klhqhsetai soi sperma

But God said to Abraam, let it not be hard before thee concerning the child, and concerning the bondwoman; in all things whatsoever Sarrha shall say to thee, hear her voice, for in Isaac shall thy seed be called

Romans 9.7:  neither, because they are Abraham’s seed, are they all children:  but, In Isaac shall thy seed be called

Hebrews 11.18:  even he to whom it was said, In Isaac shall thy seed be called

And God said unto Abraham, Let it not be grievous in thy sight because of the lad, and because of thy handmaid; in all that Sarah saith unto thee, hearken unto her voice; for in Isaac shall thy seed be called