Matthew 18:22

Who, moreover, was able to forgive sins? This is His alone prerogative: for "who remitteth sins but God alone? " and, of course, (who but He can remit) mortal sins, such as have been committed against Himself, and against His temple? For, as far as you are concerned, such as are chargeable with offence against you personally, you are commanded, in the person of Peter, to forgive even seventy times sevenfold. And so, if it were agreed that even the blessed apostles had granted any such indulgence (to any crime) the pardon of which (comes) from God, not from man, it would be competent (for them) to have done so, not in the exercise of discipline, but of power.

(Serm. 83. 3.) I am bold to say, that if he shall sin seventy-eight times, thou shouldest forgive him; yea, and if a hundred; and how oft soever he sin against thee, forgive him. For if Christ found a thousand sins, yet forgave them all, do not you withdraw your forgiveness. For the Apostle says, Forgiving one another, if any man hath a quarrel against any, even as God in Christ forgave you. (Col. 3:13.) (ubi sup.) Yet not without reason did the Lord say, Seventy times seven; for the Law is set forth in ten precepts; and the Law is signified by the number ten, sin by eleven, because it is passing the denary line. Seven is used to be put for a whole, because time goes round in seven days. Take eleven seven times, and you have seventy. He would therefore have all trespasses forgiven, for this is what He signifies by the number seventy-seven.

What then does "seventy times seven" mean? Listen, my friends, to this great mystery, this wonderful gift. When the Lord was baptized, Luke the holy Evangelist there noted down his ancestry, in what order, series and stems that generation had been reached in which Christ was born. Matthew began from Abraham and came as far as Joseph in descending generations. But Luke began to count by going back up in ascending order. Why does the one reckon in a descending and the other in an ascending order? Because Matthew set forth the generations of Christ by which he came down to us, and so he began to reckon when Christ was born from a descending order. Luke begins to reckon in reverse from when Christ was baptized. In this is the beginning of an ascension, for he begins to reckon in an ascending order. Note that in his account he enumerates seventy-seven generations! With whom did he begin his reckoning? Note carefully! He began to reckon from Christ up to Adam himself, who was the first sinner and who parented us into bondage to sin. Luke reckoned up to Adam, and so there are enumerated in toto seventy-seven generations—from Christ up to Adam and from Adam up to Christ. Note seventy-seven! So then if no generation was omitted, there is no exemption of any trespass that ought not to be forgiven. For therefore did he reckon up his seventy-seven generations, which number the Lord mentioned as to the forgiveness of sins; since he begins to reckon from the baptism, where all sins are remitted.