Genesis 21:1–8

Explore the Bible
Assistant Professor of Christian Ministries, University of Mobile

KEEPING HIS PROMISE

Genesis 21:1–8

God’s Promise Realized (1–2)

Sarah’s pregnancy was, at the time, the most celebrated of all pregnancies. Pregnant at 90 with baby No. 1. When the baby’s cry rose across the camp, there were tears and joyful shouts that would be long remembered.

God had been faithful to His word. Moses emphasized God’s faithfulness three times in the first two verses. God had told Abraham a year earlier that Sarah would bear a son within a year and that he was to name the son “Isaac” (17:15–22). Both Abraham and Sarah had laughed upon hearing God’s prophecy.

But now both Abraham and Sarah knew God had been faithful in every detail of His word. The birth of Isaac was a precise validation of God’s promise. A 90-year-old mother and her baby boy were the evidence of God’s faithfulness. This truth is vital for God’s people today. God is always true to His word. Jesus boldly declared: “For truly I say to you, until heaven and earth pass away, not an iota, not a dot, will pass from the law until all is accomplished” (Matt 5:18). This declaration by the One who Himself is the “Yes” to all the promises of Scripture means that we can and must trust every word in the Bible (2 Cor. 1:20). Every Christian ought to live in deepest trust in all of God’s Word, just as Jesus lived.

God’s Promise Remembered (3–7)

On the eighth day after birth, Abraham named and circumcised his son. The divinely given name “Isaac” means “laughter.” The name recalled the initial unbelief of the parents at the idea that a son would be born to them within a year. By naming him “Isaac,” God would have the last laugh.

The new mother Sarah joyfully celebrated the birth of her son: “God has made laughter for me; everyone who hears will laugh over me” (v. 6). The old man and his wife laughed and continued to laugh as they held tiny Laughter (Isaac) in their arms. The camp chuckled out loud. Heaven smiled.

The true heir of the Abrahamic covenant had been born. Isaac was the first person reported to have been circumcised at birth. His spiritual destiny was different from that of Ishmael who was circumcised at age 13. God poured out grace upon Abraham and his people. God had kept His word.

From the beginning Abraham had believed God. That is why he left Ur and later gave Lot his choice of the land and then went after the kings of the north when they kidnapped Lot. But now Abraham was ascending to such a level of unwavering belief that God would keep His word that later Abraham would be willing to sacrifice his son Isaac.

As followers of Christ we need to preach the gospel to ourselves and intentionally remember God’s faithfulness to accomplish his Word. God is true to His Word. God is faithful.

God’s Promise Rejoiced (8)

At least three years had passed because that was the traditional time for weaning a child in ancient Israel. Isaac was a toddler. Abraham made a great feast on that day to celebrate God’s grace and faithfulness to him and his people.

When was the last time you stopped and remembered God’s grace and faithfulness to you? When was the last time you celebrated God’s goodness poured out into your life? God can be trusted to fulfill His promises on His timetable. We need to find ways of remembering God’s faithfulness to us. His provision should be celebrated as an act of worship and thanksgiving.