Matthew names four mothers before Mary, and they are not Sarah, Rebekah and Leah.
The women
Matthew names five mothers: Tamar, Rahab, Ruth, ‘her who had been Uriah’s wife’, Mary. Luke names none. Why these four and not Sarah, Rebekah and Leah? Sinners (Jerome), Gentiles (Bauckham and others), irregular unions and initiative (Brown).
The texts
3Judah became the father of Perez and Zerah by Tamar. Perez became the father of Hezron. Hezron became the father of Ram.
4Ram became the father of Amminadab. Amminadab became the father of Nahshon. Nahshon became the father of Salmon.
5Salmon became the father of Boaz by Rahab. Boaz became the father of Obed by Ruth. Obed became the father of Jesse.
6Jesse became the father of King David. David the king became the father of Solomon by her who had been Uriah’s wife.
16Jacob became the father of Joseph, the husband of Mary, from whom was born Jesus, who is called Christ.
Readers
In order of date. Summaries are paraphrase; follow the citations for the texts themselves.
Exposition of the Gospel according to Luke, book 3
A long treatment of both genealogies. Ambrose takes up why sinful women are named, reads Tamar’s twins Perez and Zerah as the two peoples (the hand marked with scarlet drawn back, the other brother breaking through), and Ruth the Moabite, excluded by the Law but admitted, as the Church gathered from the Gentiles.
Commentary on Matthew 1:3
None of the holy women are taken into the Savior’s genealogy, but those whom Scripture reproves, so that he who came for sinners, being born of sinners, might blot out the sins of all. Hence also Ruth the Moabitess.
Homilies on Matthew 3
Matthew names the women to strip away pride in ancestry: Christ was not ashamed of these forebears, took up our shame as he took up our flesh, and so no one should be ashamed of their family’s wickedness, only of their own.
The Birth of the Messiah, 71–74
Brown adopts a proposal with ‘considerable following’: the four women before Mary share two things: an extraordinary or irregular union that outsiders might have thought scandalous, and an initiative by which each played a part in God’s plan. Matthew prepares the reader for Mary, whose pregnancy looks irregular and is the Spirit’s doing. The Gentile explanation he keeps as a subordinate motif.
Jude and the Relatives of Jesus; Gospel Women
Luke’s seventy-seven names follow 1 Enoch 10:12 (seventy generations from the binding of the Watchers to the judgment), laid out, on the model of the Apocalypse of Weeks, as eleven weeks of generations, so that Jesus belongs to the last generation. The list may come from Jesus’ own family circle, where Enoch mattered (Jude 14). Separately, with others before him, Bauckham argues the common factor among Matthew’s four women is that each was, or was held to be, a Gentile — Tamar and Rahab Canaanites, Ruth a Moabite, Bathsheba married to a Hittite.
In the tradition
Tamar · Jewish b. Sotah 10b: rather than shame Judah publicly she was ready to be burned, whence the teaching that one should throw oneself into a furnace rather than shame another in public. The blessing on Boaz, “let your house be like the house of Perez, whom Tamar bore to Judah” (Ruth 4:12), already joins her to Ruth.
Tamar · Patristic Jerome notes that Matthew lists none of the holy women but those Scripture reproves, so that he who came for sinners, being born of sinners, might blot out the sins of all (Commentary on Matthew 1:3). Ambrose reads Tamar’s twins as two peoples (Exposition of Luke, book 3).
Tamar · Scholarship Raymond Brown favors the view that Tamar, Rahab, Ruth and Bathsheba share an extraordinary or irregular union and an initiative through which God’s plan went forward, and so foreshadow Mary (The Birth of the Messiah, 73–74). Richard Bauckham, with others before him, argues the common thread is that all four were, or were reckoned, Gentiles (Gospel Women, ch. 2).
Rahab · Jewish b. Megillah 14b makes her Joshua’s wife and ancestor of eight prophets who were also priests, Jeremiah among them; R. Yehudah adds Huldah.
Ruth · Jewish The book is read at Shavuot. The rabbis resolved the Deut 23:3 problem with the ruling ‘a Moabite, not a Moabitess’ (b. Yevamot 76b).
Bathsheba · Jewish Some rabbinic readers took the ‘mother of King Lemuel’ who teaches the words of Proverbs 31 to be Bathsheba instructing Solomon (b. Sanhedrin 70b).
Mary · Scholarship Raymond Brown reads the four earlier women as foreshadowing Mary: unions that looked irregular or scandalous, through which God’s plan went forward (The Birth of the Messiah, 73–74).