In Luke 10:12 Jesus spoke of the day in which the Jews would be judged, and according to what he would later tell Annas, the high priest, in the final week of his public ministry (cf. Matthew 26:64), Jesus would be their Judge! In other words, Jesus spoke of the coming war of the Jews with Rome that would culminate in the destruction of Jerusalem and the Temple, and such a thing would be the loss of the Jews’ national status.
The urgency of the harvest of which Jesus spoke is in that context. That is, it must be reaped by a given time, and this is a parallel by the Gospel going to the Jews in the first century AD. They had only a few decades to receive it, because national judgment was approaching. As long as the Temple stood, the Apostles were able to preach the Gospel to millions of Jews from all over the world. Religious Jews came each year on pilgrimages to Jerusalem in order to worship God at the Temple. However, when the Temple was destroyed, so was the opportunity for the Gospel to go out to so many at one time. From 70 AD and onwards, evangelists were able to reap / glean only what was left in the fields by the original reapers.
In Luke 10:13-15 Jesus drew a parallel between three cities of his day along the northern shore of the Sea of Galilee, Capernaum, Bethsaida and Chorizan, and three ancient gentile cities, Sodom, Tyre and Sidon. He mentioned the works that were done in Capernaum, Bethsaida and Chorizan would have been enough to cause Sodom, Tyre and Sidon to repent of their wickedness. Nevertheless, it doesn’t seem as though Capernaum, Bethsaida or Chorizan totally rejected Jesus, because the fact is that often someone in those cities would seek Jesus’ help, especially in Capernaum.
Probably more miracles were done in Capernaum than any other city during Jesus’ public ministry. Truly, this city, as the headquarters of Jesus’ ministry, was exalted to the heavens. However, for all intents and purposes, it seems these cities seem to have simply ignored Jesus. They didn’t take his call to receive the Kingdom of God seriously. Jesus was good to have around, and all that, but these cities along the northern shore of the Sea of Galilee had other things that occupied their lives. Judgment came to them, not because they rejected Jesus, but because they ignored him and his Gospel of Peace.
Close consideration of the context will show that two judgments are implied in Luke 10:13-15. Neither Tyre nor Sidon were judged in 70 AD, during the Jewish war with Rome, but the Jewish nation was at that time destroyed. This would have been one judgment. However, since Jesus claims more mercy would be granted Tyre and Sidon than the Jewish cities that ignored the Gospel, another, second, judgment is implied in the text.
Capernaum, Bethsaida and Chroazin were judged by God in 70 AD, when the Romans destroyed the Jewish nation by conquering Jerusalem and utterly destroying its Temple. Moreover, as the ruins of these places testify to modern archaeologists, these particular cities were utterly destroyed, if not in the Jewish war with Rome, then sometime later
Tyre and Sidon were judged by God centuries before the coming of Christ. The judgment Jesus points to in Luke 10:14 (cf. Matthew 11:24) is the destruction of the Jewish nation, when Jerusalem was conquered and her walls destroyed with her Temple. If, therefore, Tyre and Sidon (which were not judged in 70 AD), are to be extended more mercy in the judgment than those cities in which Jesus performed his miracles, then another judgment must be coming in which gentile cities and Jewish cities will be judged together.
Nevertheless, looking toward 70 AD, just as Elisha inherited the authority and power of Elijah, so the Seventy (and by implication the Apostles, cf. Luke 10:4, 22:35) inherited the miracle working power and authority of Jesus (cf. Luke 10:16). Peace was offered to all, indiscriminately (cf. Luke 10:5). The one who accepted the offer of peace received Jesus as his Messiah via the Gospel preached to him, and that one was saved from impending judgment. However, the one who rejected the peace offering, rejected Jesus and inherited the judgment of the nation, which was predicted to come centuries before Jesus was born (cf. Daniel 9:26-27).