A story related to this text has a group of the very pious waiting in heaven for the judgment. As they are waiting and complaining about the wait, they begin to see some of the "sinners" they knew on earth coming into the waiting room: a corrupt politician, an itinerant woman who had been convicted of shoplifting numerous times, a prostitute, a drug addict, a man who spent most of his life in prison, etc.
With each of these arrivals, the feeling of hostility increased in the first group. They glare at the others. They talk among themselves. Within a short time, words were spoken to those others, "What makes you think you're going to get in with that evil, sinful life you lived on earth?"
"We're relying on the mercy and grace of God. What makes you so sure you're going to get in?"
"Our good lives, of course." They turned their backs to the others.
Time began to drag on for the first group. They began to complain to one another. "If those other people get in, there's no justice. After all the sacrifices we've made. It's not fair."
The Lord arrived. He turned towards the first group, "I understand you've been wondering why there has been no judgment."
"Yes!" they cried out. "We want a judgment. We want justice."
"The judgment has already taken place. You've judged yourselves. By judging these, the least of my brothers and sisters, you have judged yourselves. In rejecting them you have rejected me. You have shown yourselves unworthy of the kingdom of God."
Hare says something similar in his conclusion to this section: "We are defiled, Jesus tells us, by the unloving words that spring so readily from our mouths."