Genesis 4:15

It was suitable that, after contemplating the liberality of God, we should likewise address His clemency. For what will aliments profit us, if we are really consigned to them, as it were a bull destined for a victim? The Lord knew Himself to be the only guiltless One, and so He teaches that we beg “to have our debts remitted us.” A petition for pardon is a full confession; because he who begs for pardon fully admits his guilt. Thus, too, penitence is demonstrated acceptable to God who desires it rather than the death of the sinner. Moreover, debt is, in the Scriptures, a figure of guilt ; because it is equally due to the sentence of judgment, and is exacted by it: nor does it evade the justice of exaction, unless the exaction be remitted, just as the lord remitted to that slave in the parable his debt; for hither does the scope of the whole parable tend. …

Now, he says, the stars are the gods of destruction, which impose upon existent things the necessity of alterable generation. These, he says, Moses denominated serpents of the wilderness, which gnaw and utterly ruin those who imagined that they had crossed the Red Sea. To those, then, he says, who of the children of Israel were bitten in the wilderness, Moses exhibited the real and perfect serpent; and they who believed on this serpent were not bitten in the wilderness, that is, (were not assailed) by (evil) powers. No one therefore, he says, is there who is able to save and deliver those that come forth from Egypt, that is, from the body and from this world, unless alone the serpent that is perfect and replete with fulness. Upon this (serpent), he says, he who fixes his hope is not destroyed by the snakes of the wilderness, that is, by the gods of generation. …

Behold the seven horns of the Lamb, the seven eyes of God, the seven eyes are the seven spirits of the Lamb; seven torches burning before the throne of God seven golden candlesticks, seven young sheep, the seven women in Isaiah, the seven churches in Paul , seven deacons, seven angels, seven trumpets, seven seals to the book, seven periods of seven days with which Pentecost is completed, the seven weeks in Daniel , also the forty-three weeks in Daniel ; with Noah , seven of all clean things in the ark; seven revenges of Cain , seven years for a debt to be acquitted, the lamp with seven orifices, seven pillars of wisdom in the house of Solomon .

18. But of the enemies themselves what? “Slay them not, lest sometime they forget Thy law.” He is making request for his enemies, he is fulfilling the commandment.…Slay not them of whom the sins Thou slayest. But what is it to be slain? To forget the law of the Lord. It is real death, to go into the pit of sin; this indeed may be also understood of the Jews. Why of the Jews, “Slay not them, lest sometime they forget Thy law”? Those very enemies of mine, that have slain me, do not Thou slay. Let the nation of the Jews remain: certes conquered it hath been by the Romans, certes effaced is the city of them, Jews are not admitted into their city, and yet Jews there are. For all those provinces by the Romans have been subjugated. …

Gen. iv. 15 , he understands to mean “the slayer of Cain shall complete the sevenfold vengeance which is to be wreaked upon him.”

2. You have asked for a solution of that famous passage which is everywhere interpreted in different senses, “Whosoever slayeth Cain will exact vengeance for seven sins.” Your question shews that you have yourself carefully observed the charge of Paul to Timothy, for you are obviously attentive to your reading. You have moreover roused me, old man that I am, dull alike from age and bodily infirmity, and from the many afflictions which have been stirred up round about me and have weighed down my life. Fervent in spirit as you are yourself, you are rousing me, now benumbed like a beast in his den, to some little wakefulness and vital energy. The passage in question may be interpreted simply and may also receive an elaborate explanation. The simpler, and one that may occur to any one off hand, is this: that Cain ought to suffer sevenfold punishment for his sins.

3. But readers, gifted with greater curiosity, are naturally inclined to probe into the question further. How, they ask, can justice be satisfied seven times? And what are the vengeances? Are they for seven sins committed? Or is the sin committed once and are there seven punishments for the one sin? Scripture continually assigns seven as the number of the remission of sins. “How often,” it is asked, “shall my brother sin against me and I forgive him?” (It is Peter who is speaking to the Lord.) “Till seven times?” Then comes the Lord’s answer, “I say not unto thee, until seven times, but, until seventy times seven.” Our Lord did not vary the number, but multiplied the seven, and so fixed the limit of the forgiveness. After seven years the Hebrew used to be freed from slavery. …