Treasury of Scripture Knowledge

Summary

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.

Bible References

In isaac

Romans 9:7
they are not all children of Abraham because they are Abraham's descendants. The promise was, In Isaac shall thy posterity be called.
Hebrews 11:18
of whom it had been said, It is through Isaac that your posterity will be traced.