Answer: The early verses of Matthew 10 consist of a group of instructions to the disciples sent on a "training mission" -- specifically focused on their lives, mission, and training -- in that time and place, there and then. It does seem that verse 17 takes on a different tone -- more in the future -- after Christ’s death -- when the disciples would become apostles, the church was founded, etc.

In that context, Jesus is telling his disciples in verse 23 that they will be persecuted. In fact, this portion of Matthew 10 – verses 17-23 – is all about future persecution that Jesus’ disciples could expect and did encounter. The Bible’s own history of the early church, recorded in Acts, verifies that persecution. They would not be finished going over the cities of Israel before the Son of man comes -- what does that mean?

The book of Acts and other New Testament books shows that the early church "finished" with the cities of Israel quickly – after Jerusalem, Joppa, and a few other places, the main focus of evangelism we know of was outside of Palestine.

Applicatin to us: Christ followers are encouraged never to give up, not to become discouraged, but when persecution is encountered, if necessary, to move on. This principle was reiterated in Acts 1:8 and followed and demonstrated throughout the book of Acts.

What does the phrase "Son of Man comes" imply? In one sense, the son of Man came to the earth as Jesus – he had already come, the first time, when Jesus uttered these words. Was Jesus referring to this Second Coming here? Or, does this verse have something to do with the "end times" – eschatology that Jesus gave in this same book -- in Matthew 24 -- that we might explain as being fulfilled in the destruction of Jerusalem in 69-70 A.D.? Did the Son of Man come – in the sense that his prophecy of the destruction of Jerusalem was fulfilled? Or, perhaps the "Son of Man’s coming" could be seen as the coming of Jesus to live in the lives of those who accept him, in the new life that he imparts to those who believe – and that coming has been happening since the beginning of the church in Acts 2?

I don’t know that there is any perfect explanation for what the references in Matthew 10 to "coming of the Son of Man" might be. However, I do know that much of the persecution and hardship that Jesus prophesies about was personally experienced by his immediate audience to whom he first spoke these words. And much has been experienced in the history of the church over the past two thousand years. And, indeed, some is happening in the world today, in countries where Christians are suffering intense persecution, much like that spoken of in this passage.