John Gills Exposition of the Bible Commentary - Genesis 21:2
For Sarah conceived ,.... This explains what is meant by the Lord's visiting her, and doing to her according to his word, see Hebrews 11:11 , and bare Abraham a son in his old age ; which circumstance is remarked, that the favour might appear the greater, and the more wonderful; or, "unto", or "for his old age" F14 לזקניו "pro senectute ejus", Vatablus; "senectuti ejus", Junius & Tremellius. , for the comfort of him in his old age, who having lived so many years under the... read more
Matthew Henry's Complete Commentary - Genesis 21:1-8
Few under the Old Testament were brought into the world with such expectation as Isaac was, not for the sake of any great person eminence at which he was to arrive, but because he was to be, in this very thing, a type of Christ, that seed which the holy God had so long promised and holy men so long expected. In this account of the first days of Isaac we may observe, I. The fulfilling of God's promise in the conception and birth of Isaac, Gen. 21:1, 2. Note, God's providences look best and... read more