211 The Lord visited Sarah as he had said, and the Lord did to Sarah as he had promised. 2 And Sarah conceived, and bore Abraham a son in his old age at the time of which God had spoken to him. 3 Abraham called the name of his son who was born to him, whom Sarah bore him, Isaac. 4 And Abraham circumcised his son Isaac when he was eight days old, as God had commanded him. 5 Abraham was a hundred years old when his son Isaac was born to him. 6 And Sarah said, "God has made laughter for me; every one who hears will laugh over me." 7 And she said, "Who would have said to Abraham that Sarah would suckle children? Yet I have borne him a son in his old age."
8 And the child grew, and was weaned; and Abraham made a great feast on the day that Isaac was weaned.
Matthew Henry's Commentary on Genesis 21:1-8
Commentary on Genesis 21:1-8
(Read Genesis 21:1-8)
Few under the Old Testament were brought into the world with such expectations as Isaac. He was in this a type of Christ, that Seed which the holy God so long promised, and holy men so long expected. He was born according to the promise, at the set time of which God had spoken. God's promised mercies will certainly come at the time which He sets, and that is the best time. Isaac means "laughter," and there was good reason for the name, Psalm 22:9,10; Hosea 11:1,2.