“Jesus went throughout Galilee, teaching in their synagogues and proclaiming the good news of the kingdom and curing every disease and every sickness among the people” (Matt 4:23). So we hear at the end of the Gospel passage offered by the lectionary for this coming Sunday.
This verse contains a very significant statement, when it refers to “their synagogues”. It is the passing reference, a seemingly fleeting, yet quite significant, reference to “their synagogues”. Not “our synagogues”, not even “the synagogues”, but “their synagogues” (Matt 4:23; 9:35; 10:17). There is a note of tension in this description; perhaps a hint of a conflict simmering between “our synagogues” and “their synagogues”?
In fact, the third of these texts (Matt 10:17) equates those who were flogging disciples in “their synagogues” as “wolves”—perhaps harking back to the prophetic denunciations of priests (Ezek 22:23–27), judges (Zeph 3:1–5), and Chaldeans (Hab 1:6–11). We might also note the devastating depiction of Benjamin as “a ravenous wolf, in the morning devouring the prey, and at evening dividing the spoil” (Gen 49:27). That is how “their synagogues” are depicted in Matthew’s book of origins.
Synagogues were the places in towns and villages throughout Judea and Galilee where the Torah was taught, through memorisation, debate, and discussion. These debates about Torah in synagogues across the land took on an intensified form after 70 CE. The survival of Judaism without the Temple depended on the faithful practice of the Torah: all of its commandments and instructions were there to shape a whole way of life for the people, to maintain the covenant that their ancestors had entered into with the Lord God. So there was much debate about how to keep all those commandments appropriately and faithfully.
The polemic in Jesus’ debates with the Pharisees, and the warnings that are uttered to Israel, show that Matthew still had hope that his ideas would become normative for all Jewish people. What was being taught in “our synagogues” at the time of the writing of this Gospel, some decades after the time of Jesus, was somewhat different from what was being taught in “their synagogues”—the places of teaching for the scribal authorities of the time. And this was despite the fact that Jesus himself had taught in “their synagogues”.
If the author of this Gospel knew anything about what was happening elsewhere in the movement initiated by the life and teachings of Jesus, he would have known about the gathering strength of the movement led by Saul of Tarsus, for whom strict obedience to Torah was of less importance than belief in Jesus as Messiah.
This arm of the movement was opening a door wide for Gentiles, who did not follow the Torah, to belong to such communities. This had been underway since the 50s. It had gained momentum by the late 60s and would become the dominant form of Christianity later in the second century. At the time that Matthew’s book of origins was being compiled, however, there were still people maintaining fidelity to the covenant of Israel, holding fast to the commandments and ordinances of the Torah, who nevertheless confessed Jesus to be Messiah—the chosen one of God, the Teacher supreme of Torah.
It was perhaps with an awareness of this growing trajectory of less attachment to Torah within the Jesus movement, that Matthew’s Gospel was created—to insist on the centrality and priority of the traditional teaching of Jesus, the Torah-observant Jew, whom God had chosen as the anointed one. And the picture that he offers of Jesus is a resolutely Jewish one. Remembering that Jesus said “Go nowhere among the Gentiles” (10:5) makes perfect sense in this context.
The Jesus who is presented in this Gospel is a fearful and demanding figure. In his capacity as the disciple’s Rabbi and as God’s Messiah, Jesus frequently promises (or threatens) judgement (5:21–26; 7:1–2; 10:15; 11:21–24; 12:36–37; 19:28–30; 21:33–44; 22:1–14; 24:29–31, 36-44, 45–51; 25:1–13, 14–30, 31–46; 26:64). Many of these declarations occur in eschatological contexts, where Jesus is warning about the punishment that is to come unless righteous-justice is followed in the present. The threat of this judgement is constantly before the people, calling them to lives of righteous-justice, which is the hallmark of the kingdom which God has in store for God’s people—the central message that Jesus persistently proclaims.
An Informed Faith 
There’s a structural aspect here, too, a nice inclusio. He says J. was teaching & healing: then come several chapters of typical teaching, then some of typical healings then this summary: this is all largely scene-setting, before the narrative gets started for real, in 9 & 10: J. looks on crowd w/ compassion — then at the end, J. looks on the two blind men who call Son of David w/ compassion: he heals them, and alone of the healings, they (now that they can see … that it’s not just S.o.D.?) follow him.
Given the structure & also the development, I’m disinclined at the moment to read too much into “their” at this first occurrence. Although, by the end, the leadership class is harshly criticized.