Tertullian · a new plain-English translation from the original language
Having observed God's generosity, it followed that we should also beg his mercy. What good would food do us, if we were reckoned to him as no better than a bull led to the slaughter? The Lord knew that he alone was without fault. So he teaches us to pray FORGIVE US OUR DEBTS. Confession is the plea for pardon, because whoever asks pardon confesses a fault. In this way, too, repentance is shown to be acceptable to God, since it is what he desires, not the sinner's demise. Now in Scripture, debt is a figure for sin, which in the same way is owed to judgment and exacted by it, and cannot escape the justice of the exaction unless the exaction is remitted — just as that master forgave his servant the debt. That is what the whole parable is aimed at. For the same servant, once freed by his master, does not likewise spare his own debtor, and for that reason, reported to his master, is handed over to the torturer to pay the last farthing — that is, even the smallest debt — and this fits exactly with our profession that WE TOO FORGIVE OUR DEBTORS. Elsewhere, too, in the same vein he says, Forgive, and you will be forgiven. And when Peter asked whether he should forgive his brother seven times, he answered, No — seventy times seven, reforming for the better the law by which, in Genesis, vengeance for Cain was reckoned sevenfold, and for Lamech seventy-sevenfold.