Verse 18:[1] Now these are the generations of Pharez: (1 Chron. 2:4, etc.; Matt.1:3) Pharez begat Hezron…
[These are the generations of Pharez] An account of those that descended from Pharez. Generation, in the place of those generated; like nativity, in the place of natis, those born; captivity, in the place of captives; custody, in the place of the custodians (Drusius).
Verse 19:[2] And Hezron begat Ram, and Ram begat Amminadab…
[Aram (thus the Septuagint and Matthew,[3] Malvenda), רָם] Ram. Thus he is also called in 1 Chronicles 2 (Bonfrerius).
Verse 20:[4] And Amminadab begat (Num. 1:7) Nahshon, and Nahshon begat (Matt. 1:4, etc.) Salmon (or, Salmah[5])…
[Salmon, שַׂלְמָה] Salmah. The same is also called שַׂלְמוֹן/Salmon in the following verse (Vatablus, Drusius). Now, this genealogy, taken verbatim from this little book, Matthew inserted verbatim in the genealogy of Christ; and the Holy Spirit willed that it be extant, so that we might be certain that Jesus of Nazareth is that promised redeemer of the world, whom the Prophets said would arise from the posterity of the Patriarch Judah[6] and of David[7] (Osiander).
Verse 21:[8] And Salmon begat Boaz, and Boaz begat Obed…
Verse 22:[9] And Obed begat Jesse, and Jesse begat (1 Chron. 2:15; Matt. 1:6) David.
Obed…David: How can this be a true genealogy, seeing by this means four persons take up three hundred and eighty years, which were between Salmon and David, and consequently every one of them must beget a son when he was very old? Answer 1. It is not certain that each of these was the immediate parent of him whom he is said to beget; for sometimes grandfathers are said in Scripture to beget their grandchildren, to wit, by the intervention of their immediate sons; whereof instances have been given. And sometimes in genealogies whole generations are omitted, as may appear by Ezra 7:2, compared with 1 Chronicles 6:8 and by Matthew 1:8, which might be done here for divers reasons now unknown. 2. There are many examples even in profane writers, both ancient and modern, of persons that have not only lived one hundred and twenty and one hundred and thirty years and upwards, but have been vigorous and have begotten children at above one hundred years old; and of women that have conceived and born children at the age of fifty, sixty, yea, seventy years. And therefore if it were so in these more ancient times, when men were longer lived, and under the law, when long life was expressly promised to the obedient, and in persons of strong constitutions and sober conversations, such as some of these are known to have been, and the others may justly be presumed to be such, it is not strange, nor in the least incredible.
[1] Hebrew: וְאֵ֙לֶּה֙ תּוֹלְד֣וֹת פָּ֔רֶץ פֶּ֖רֶץ הוֹלִ֥יד אֶת־חֶצְרֽוֹן׃
[2] Hebrew: וְחֶצְרוֹן֙ הוֹלִ֣יד אֶת־רָ֔ם וְרָ֖ם הוֹלִ֥יד אֶת־עַמִּֽינָדָֽב׃
[3] Matthew 1:3: “And Judas begat Phares and Zara of Thamar; and Phares begat Esrom; and Esrom begat Aram (τὸν Ἀράμ)…”
[4] Hebrew: וְעַמִּֽינָדָב֙ הוֹלִ֣יד אֶת־נַחְשׁ֔וֹן וְנַחְשׁ֖וֹן הוֹלִ֥יד אֶת־שַׂלְמָֽה׃
[5] Hebrew: שַׂלְמָה.
[6] See Genesis 49:8-12.
[7] See, for example, Isaiah 11:1, 10; Luke 20:41; Revelation 5:5; 22:16.
[8] Hebrew: וְשַׂלְמוֹן֙ הוֹלִ֣יד אֶת־בֹּ֔עַז וּבֹ֖עַז הוֹלִ֥יד אֶת־עוֹבֵֽד׃
[9] Hebrew: וְעֹבֵד֙ הוֹלִ֣יד אֶת־יִשָׁ֔י וְיִשַׁ֖י הוֹלִ֥יד אֶת־דָּוִֽד׃
Matthew Henry: 'Ruth is hereby brought in among the ancestors of David and Christ, which was the greatest honour. The genealogy is here drawn from Pharez, through Boaz and Obed, to David, and so leads towards the Messiah, and therefore it is not an endless genealogy.'