Genesis 21:2

Gen 21:2 For Sarah conceived, and bare Abraham a son in his old age, at the set time of which God had spoken to him.

Ver. 2. For Sarah conceived.] By the force of her faith, though at first she faltered. {Heb 11:11}

And bare Abraham a son in his old age.] Beatae senectutis et emeritae fidei filium , as one well calleth Isaac. {a} St Paul, for this, saith he was "born after the Spirit". {Gal 4:29}

{a} Bucholcer.

John Trapp, A Commentary or Exposition upon All the Books of the Old and New Testament (1647–1656) — public domain. Text from a community e-Sword module.

Gen 21:2. Sarah conceived — By faith Sarah received strength, (Heb 11:11,) to conceive seed, God, according to his promise, giving that strength. Abraham was old, and Sarah old, and both as good as dead, and then the promise took place.

Joseph Benson's Commentary on the Old and New Testaments (1811–1818) — public domain. Text from a community e-Sword module.

Therefore the miracle was greater.

Geneva Bible (1599) marginal notes — public domain. Text via Bolls.life.

2. She bare Abraham a son. This is said according to the accustomed manner of speaking; because the woman is neither the head of a family, nor brings forth properly for herself, but for her husband. What follows, however, is more worthy of notice, In his old age, at the set time, which God had predicted: for the old age of Abraham does, not a little, illustrate the glory of the miracle. And now Moses, for the third time, recalls us to the word of God, that the constancy of his truth may always be present to our minds. And though the time had been predicted, alike to Abraham and to his wife, yet this honor is expressly attributed to the holy man; because the promise had been especially given on his account. Both, however, are distinctly mentioned in the context.

John Calvin's Commentaries (1540-1563) — public domain. Text from the Calvin Translation Society English edition (1840s-50s) via the Christian Classics Ethereal Library (ccel.org). Calvin's coverage is partial (roughly two-thirds of the Bible); uncommented books and verses are honest gaps, never fabricated. The 19th-century editor's footnotes and remarks are omitted so the notes are faithfully Calvin's own voice.

2. in his old age] Cf. Gen_21:7, Gen_18:11, Gen_24:36, Gen_37:3, Gen_44:20 (al+l from J); meaning literally “to his old age.”

at the set time] Cf. Gen_17:21 (P).

It is to this verse that allusion is made in Heb_11:11, “by faith even Sarah herself received power to conceive seed, when she was past age, since she counted him faithful who had promised.”

The Cambridge Bible for Schools and Colleges (gen. ed. J. J. S. Perowne; Cambridge University Press, 1878–1918) — public domain. Text from a community e-Sword module.

For Sarah conceived,.... This explains what is meant by the Lord's visiting her, and doing to her according to his word, see Heb 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" (n), for the comfort of him in his old age, who having lived so many years under the promise of a son, and in the expectation of one, even of the promised seed, from whom the Messiah should spring, now has one, than which nothing could yield him greater consolation:

at the set time of which God had spoken to him, Gen 17:21; God was not only faithful in fulfilling his promise, but in keeping the exact time of it.

(n) "pro senectute ejus", Vatablus; "senectuti ejus", Junius & Tremellius.

John Gill's Exposition of the Whole Bible (1746–1763) — public domain (CC PDM 1.0). Text via the HelloAO Bible API.

In his old age, or, for his old age, i.e. for the comfort of his old age.

Matthew Poole's English Annotations on the Holy Bible (1683–1685) — public domain. Text from a community e-Sword/MySword module.

2. At the set time — See Gen_17:21.

Daniel D. Whedon (gen. ed.), Commentary on the Old and New Testaments (1874–1909) — public domain. Text from a community e-Sword module.

For Sarah conceived, through faith receiving strength from God for that purpose; (Heb_11:11) the fruit of the womb, in every instance God"s handiwork, (Isa_44:2) being in her case a special gift of grace and product of Divine powerand bare the usual construction (Gen_29:32 Gen_30:5) is here somewhat modified by the Jehovist (Kalisch); but the clause may be compared with Gen_30:22, Gen_30:23, commonly assigned to the ElohlstAbraham (literally, to Abraham) a son in his old age, literally, to his old age; eijv to ghrav (LXX)at the set time (vide Gen_17:21 Gen_18:10, Gen_18:14) of which God had spoken to him. God"s word gave Abraham strength to beget, Sarah to conceive, and Isaac to come forth. Three times repeated in two verses, the clause points to the supernatural character of Isaac"s birth.

The Pulpit Commentary (1880–1919), ed. H.D.M. Spence-Jones & Joseph S. Exell — public domain. Text from a community e-Sword module.

Sarah conceived - Sarah by faith, received strength to conceive, Heb. xi, 11. God therefore, by promise, gave that strength. Abraham was old, and Sarah old, and both as good as dead, and then the word of God took place.

John Wesley, Explanatory Notes Upon the Whole Bible (1754–1765) — public domain. Text via the GEBible commentary corpus.

למועד אשר דבר אתו Render it as Onkelos translates: “At the appointed time which He had spoken: — the time He had said and appointed. When He had said to him (18:4) “At the set time I will return unto thee”, He scratched a mark in the wall and said to him (Genesis 53:6), “When the sunrays touch this mark next year she will bear a son” (Yalkut Shimoni on Torah 59:1).

Rashi on the Tanakh — English translations: “The Judaica Press complete Tanach with Rashi, translated by A. J. Rosenberg” (CC BY 4.0); “Pentateuch with Rashi's commentary by M. Rosenbaum and A.M. Silbermann, 1929-1934” (public domain); “The Metsudah Tanach series, Lakewood, N.J” (CC BY 4.0); and “The Book of Joshua, Metsudah Publications, 1997” (CC BY 4.0). Text via Sefaria.

ותהר, seeing that the conception had not been mentioned in the previous verse, the Torah now reports conception and birth as if it had been a consecutive activity. We find a similar construction in Genesis 4,1 ותהר ותלד את קין, “Chavah conceived and gave birth to Kayin.”

לאברהם, as G’d had said “אשר תלד לך שרה,” “whom Sarah will bear for you.” This is a customary form of syntax, as for instance in 16,15 ותלד הגר לאברהם בן, or Exodus 21,4 וילדה לו בנים ובנות, and many similar examples. A woman is considered similar to the earth in this respect, i.e. just as the earth yields fruit for its owners, so a woman produces children for her husband after he had planted his seed in her. The child was named after its father.

לזקוניו, the Torah writes this so that we better understand why Sarah had laughed when she had heard the prophecy in 18,12 and had said that her husband was too old to sire children. Another reason for the expression לזקוניו is to inform us that whereas Sarah had regained her youth at that time and had ovulated again after having ceased to do so for many years, Araham did not experience any rejuvenation, but sired a child in spite of not shedding signs of old age. There are some words in the Hebrew language which always appear in the plural mode, זקונים is one of them, so are נעורים and בתולים.

אשר דבר אותו, the word אותו here is the same as if the Torah had written עמו, “with him.”

Radak on the Tanakh — English translations: “Sefaria Community Translation” (CC0 1.0 (public-domain dedication)); “Eliyahu Munk, HaChut Hameshulash” (CC BY 4.0); “Rabbi Mike Feuer, Jerusalem Anthology” (CC BY 4.0); and “R. David Kimhi on the first book of Psalms, Translated by R.G. Finch, London, 1919” (public domain). Text via Sefaria.