Truly, I say to you, it will be more bearable on the day of judgment for the land of
Sodom and Gomorrah than for that town.
Jesus also makes clear that retribution delayed is not retribution canceled. The unrepentant home or village will suffer more than Sodom and Gomorrah did. Here he is citing the case of the two wealthy salt-trading towns near the Dead Sea which were annihilated by God during the time of Abraham. The story is told in Genesis, chapters 18 and 19. Abraham is camped near Mamre when three men approach. Abraham recognizes them as special. He prepares a feast with a fatted calf and Sarah makes cakes. His hospitality is on display. He treats his guests very well. While discussing the matter, two of his guests depart to investigate the goings on in Sodom and Gomorrah. When these two arrive, the people of the town attempt to force the two visitors to engage in sexual relations. Abraham's nephew Lot attempts to dissuade the citizens, spiriting the two guests into his home and even offering his two daughters for the crowds to entertain themselves with. Such a contrast with Abraham's hospitality. Abraham cares for and feeds his guests royally; Sodom and Gomorrah wish to rape their guests. The two divine messengers tell Lot and his family to run away and not look back. The two cities are annihilated with fiery hail and brimstone.
Hospitality toward strangers is a hallmark of the peoples of "the Book" -- peoples who recognize the Old Testament as the Word of God. Jews, Christians, and Islamic folk all hold to the importance of hospitality, because we never really know when there may be divine implications of a lack of hospitality.
With this promise/curse, Jesus makes clear the hospitality rules still apply. They particularly apply to the people who carry the Good News. That means you and me. But God is the one who will repay the unrepentant in His time and in His way. Leave vengeance to Him. Later on in Jesus' ministry, a Samaritan town will reject Jesus and the disciples' entrance into that town, and James and John will ask the Lord if they should call fire down on that town, (Luke 9: 51-56). Jesus rebukes James and John, and they go on to the next town.
Final judgment is solely in the hands of the Final Judge, not us. And that is a good thing. Leave that judgment and anger to him. Shake the dust from your feet, move on to the next town, and don't look back.
Remember Whose you are,