211 The Lord dealt with Sarah as he had said, and the Lord did for Sarah as he had promised. 2 Sarah conceived and bore Abraham a son in his old age, at the time of which God had spoken to him. 3 Abraham gave the name Isaac to his son whom Sarah bore him. 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 Now Sarah said, "God has brought laughter for me; everyone who hears will laugh with me." 7 And she said, "Who would ever have said to Abraham that Sarah would nurse children? Yet I have borne him a son in his old age."
8 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.