Shortly after the statements of verses fifteen through seventeen, Jesus makes His famous and popular statement of “For where two or three are assembled in My name, I am there among them” (Matthew 18:20). So many tend to revel in this statement, while also tending to forget that it is offered in the context of conflict and what appears to be discipline. This discipline, it shall be seen, is not necessarily the discipline of the individual in question that is being brought before groups of brothers or before the church, but rather the teachings of Jesus that are meant to provide a disciplining effect for the covenant community---guiding their actions and behaviors.
Along with this, one does well to recognize the fact that these words on offer by Jesus, as reported by Matthew and as placed in the structure of His narrative concerning Jesus, follows immediately from the parable of the lost sheep. That parable presents a shepherd leaving ninety-nine sheep to go after just one that is lost, and closes with Jesus saying “In the same way, your Father in heaven is not willing that one of these little ones be lost” (18:14). This statement must be kept in mind when Jesus is heard to say “treat him like a Gentile or a tax collector.”
At the same time, the reader is forced to come to grips with the fact that Jesus, after speaking about His presence in the midst of gathered ones, is reported to have conducted a conversation with Peter, who has asked about the necessity of multiple offerings of forgiveness. Jesus effectively informs Peter that forgiveness must be limitless. This demands to be understood within the narrative flow of the entirety of Matthew’s Gospel, as well as the flow of the section in which it is to be found (not to mention that seventy times seven, or 490, would have a strong connection to Daniel and the end of exile), so it can be asserted that it does have bearing on the way Jesus’ insistence in regards to treatment as a Gentile or tax collector is to be understood.
The questions that must be asked are “What would this mean to Jesus’ audience?” and “What would this mean to Matthew’s audience?” These are interesting, provocative, and interesting questions. Jesus’ audience would not be unaware of His activities to that point. They would have known who it was with which Jesus surrounded himself, and they would have known things that were thought and said about Jesus by both His supporters and His detractors. In the case of Matthew’s audience, one must never lose sight of the fact that Matthew’s written narrative---apparently drawing from Mark, perhaps some unknown written collections of Jesus’ teaching, and a community-controlled oral tradition---would have been composed for a largely oral community, and would have been designed to be orally performed in a communal setting, presented from start to finish in a single sitting.
So what would both Jesus’ and Matthew’s audience already know when it comes to their hearing of the words recorded in the eighteenth chapter, that would inform their comprehension of Jesus’ words about Gentiles and tax collectors? In the fourth chapter, Matthew records Jesus’ re-location from Nazareth to Capernaum (in the region of Zebulun and Naphthali). This is picked up on as a historical actualization of words from Isaiah, which read “Land of Zebulun and land of Naphthali, the way by the sea, beyond the Jordan, Galilee of the Gentiles---the people who sit in darkness have seen a great light, and on those who sit in the region and shadow of death a light has dawned” (4:15-16). Though it is not possible to come anywhere close to presuming that Jesus’ audiences would have made this connection, Matthew’s audience hears this reference to a light to the Gentiles very early on in the telling of the Jesus story.