Subtle repetition in the story about the Unmerciful Debtor. The meaning of prison and the selling of his wife and children. The great (and common among men) sin of the debtor. More to the point, WHY do we do good to others? We give the best answer - not about commandments, or rules, or rewards or punishments. The Transfiguration, celebrated the day before, helps us to form the answer. Matthew 18:23-35