15 我要使你和女人结仇，你的后代和女人的后代也要彼此为仇，女人的后 必伤你的头，你必伤他的脚跟。”
Introduction: In the previous post we read how the Lord had given Abram a promise of land for his descendants in the most solemn declaration of blessing and judgment ever given to mankind. Why was this given to Abram in his weakness? It was because Abram trusted him.
Five more years have passed. But still he has no son and the land is not his.
What could Abram do? What can any believer do when heaven is not visible to our eyes, and we only see daily difficulties.
A Son by Any Means
Sarai, who did not believe, suggested to Abram something he could do as a means of getting a son. He agrees, and son called Ishmael is born to Abram through Sarai’s servant girl when he is 86.
Then Sarai feels acutely the shame of not being mother to the son. And Abram seems to realise that this is not the right means. You can read about it in Genesis Chapter 16:1-16.
Fifth Covenant Declaration by the Lord
Another 13 years have passed. The repeated covenant promise of Almighty God was generous. Abram’s children would be numberless as dust of the earth (Gen 13:15), and boundless as the stars spread across the sky. The great sworn promise was all about what God would do. Was there nothing Abram could do?
Abram’s Part in the Covenant
Yes, there was something that Abram could do, and he must do it; he must be blameless (verse 1), with a heart that always wanted to be clean. And, yes, he wanted that; and the Lord gave him the new name Abraham, meaning ‘Father of a Multitude’. His very name would be proclaiming the grace of God shown to him for another 76 years until he died (Genesis 25:7, 8).
The Sign of God’s Covenant Grace
There was something else that Abraham could do, and must do, and would do. He and his children and his dependants must receive in their flesh the circumcision sign which showed that they, his household, were included in God’s blessing.
At Last a Son for Sarai
Abraham laughs because God’s ways are so wonderful. Sarai will be mother of nations and kings, her new name ‘Sarah’ meaning ‘Princess’. And her son would have the name ‘Isaac’, meaning ‘He laughs’. The future promised in the covenant would be fulfilled through Isaac, not through Ishmael. However, Ishmael would also be blessed.
That same day everyone, including Ishmael whom Abraham loved (v.18), received in the flesh the sign of faith.