Luke 1:13-20

but the angel said to Zacharias, don't be afraid, Zacharias, for your prayer is heard: and your wife Elizabeth shall bear you a son, whom you shall name John:

Romans 9:6-9

However, the divine promise cannot but have its effect. for they are not the whole of Israel, who are descended from Israel:

Galatians 4:28-31

Now we, my brethren, as Isaac was, are the children of the promise.

Treasury of Scripture Knowledge

Summary

And God said, Sarah thy wife shall bear thee a son indeed; and thou shalt call his name Isaac: and I will establish my covenant with him for an everlasting covenant, and with his seed after him.

General references

Bible References

General references

Luke 1:55
which he promised to our forefathers, to Abraham, and to his posterity for ever."