7 Consider then, Brethren; every man begins from Baptism; he goes out free, the “ten thousand talents” are forgiven him; and when he goes out, he will soon find some fellow-servant his debtor. Let him note then, what sin itself is; for the number eleven is the transgression of the law. For the law is ten, sin eleven. For the law is denoted by ten, sin by eleven. Why is sin denoted by eleven? Because to get to eleven, there is the transgression of the ten. But the due limit is fixed in the law; and the transgression of it is sin.
Now when you have passed beyond the ten, you come to eleven. This high mystery was figured out when the tabernacle was commanded to be built. There are many things mentioned there in number, which are a great mystery. Among the rest, curtains of haircloth were ordered to be made not ten, but eleven; because by haircloth is signified the confession of sins. Now what do you require more? Would you know how that all sins are contained in this number “seventy-seven”? Seven then is usually put for a whole; because in seven days the revolution of time is completed, and when the seventh is ended, it returns to the first again, that the same revolution may be continued.
In such revolutions whole ages pass away: yet there is no departure from the number seven. For He spoke of all sins, when He said “seventy times seven;” for multiply that eleven seven times, and it makes seventy-seven. Therefore would He have all sins forgiven, for He marked them out by the number seventy-seven. Let no one then retain against himself by refusing to forgive, lest it be retained against him, when he prays. For God says, “Forgive, and you shall be forgiven.” For I have forgiven you first; you at least forgive after that.
For if you will not forgive, I will call you back, and put upon you again all that I had remitted to you. For the Truth does not speak falsely; Christ neither deceives, nor is deceived, and He has said at the close of the parable, “So likewise shall your Father which is in heaven do unto you.” Thou findest a Father, imitate your Father. For if you will not imitate Him, you are devising to be disinherited. “So likewise” then “shall My heavenly Father do also unto you, if you from your hearts forgive not every one his brother their trespasses.”
Say not with the tongue, “I forgive,” and put off to forgive in the heart; for by His threat of vengeance God shows you your punishment. God knows where you speak. Man can hear your voice; God looks into your conscience. If you say, I forgive; forgive. Better is it that you should be violent in words, and forgive in the heart, than in words be soft, and in the heart relentless.
Source: Sermons on Selected Lessons of the New Testament (New Advent)