What did God tell Abraham in Genesis 21:12 about Ishmael and Sarah's demand?
God told Abraham not to be grieved because of the lad Ishmael or the bondwoman, and to hearken unto Sarah's voice, for in Isaac shall thy seed be called. The seed is singular here, pointing to Christ, not the multitudes from the twelve tribes.
Les explains that in Genesis 21, Ishmael had reached the age of tormenting little Isaac, who was probably five, so Ishmael and his mother Hagar were sent out at God's instruction. God then told Abraham in verse 12 not to be grieved over the lad or the bondwoman, and to hearken unto Sarah's voice, because in Isaac shall thy seed be called. Les stresses that the Hebrew word for seed, Zerah, is like the English word sheep—it can be singular or plural depending on context. Here it is singular, not referring to the millions from the twelve tribes, but to Christ.
And God said unto Abraham, Let it not be grievous in thy sight because of the lad, and because of thy bondwoman; in all that Sarah hath said unto thee, hearken unto her voice; for in Isaac shall thy seed be called.