Charles Ellicott Commentary Matthew 18:33

"shouldest not thou also have had mercy on thy fellow-servant, even as I had mercy on thee?" — Matthew 18:33 (ASV)

Even as I had pity on you—The comparison of the two acts, and the implied assumption that the pity of the one act would follow the pattern of the other, was, we may believe, designed to lead the disciples to the true meaning of the prayer they had been taught to use: Forgive us our debts, as we forgive our debtors.