Genesis 4:15

15. whosoever slayeth Cain--By a special act of divine forbearance, the life of Cain was to be spared in the then small state of the human race. set a mark--not any visible mark or brand on his forehead, but some sign or token of assurance that his life would be preserved. This sign is thought by the best writers to have been a wild ferocity of aspect that rendered him an object of universal horror and avoidance.

Robert Jamieson, A. R. Fausset & David Brown, 1871 · public domain

Verse 15 The Lord set a mark upon Cain - What this mark was, has given rise to a number of frivolously curious conjectures. Dr. Shuckford collects the most remarkable. Some say he was paralytic; this seems to have arisen from the version of the Septuagint, Στενων και τρεμων εση, Groaning and trembling shalt thou be. The Targum of Jonathan ben Uzziel says the sign was from the great and precious name, probably one of the letters of the word Yehovah. The author of an Arabic Catena in the Bodleian Library says, "A sword could not pierce him; fire could not burn him; water could not drown him; the air could not blast him; nor could thunder or lightning strike him." The author of Bereshith Rabba, a comment on Genesis, says the mark was a circle of the sun rising upon him. Abravanel says the sign was Abel's dog, which constantly accompanied him. Some of the doctors in the Talmud say that it was the letter ת tau marked on his forehead, which signified his contrition, as it is the first letter in the word תשובה teshubah, repentance. Rabbi Joseph, wiser than all the rest, says it was a long horn growing out of his forehead! Dr. Shuckford farther observes that the Hebrew word אית oth, which we translate a mark, signifies a sign or token. Thus, Gen 9:13, the bow was to be לאית leoth, for a sign or token that the world should not be destroyed; therefore the words, And the Lord set a mark upon Cain, should be translated, And the Lord appointed to Cain a token or sign, to convince him that no person should be permitted to slay him. To have marked him would have been the most likely way to have brought all the evils he dreaded upon him; therefore the Lord gave him some miraculous sign or token that he should not be slain, to the end that he should not despair, but, having time to repent, might return to a gracious God and find mercy. Notwithstanding the allusion which I suppose St. Paul to have made to the punishment of Cain, some think that he did repent and find mercy. I can only say this was possible. Most people who read this account wonder why Cain should dread being killed, when it does not appear to them that there were any inhabitants on the earth at that time besides himself and his parents. To correct this mistake, let it be observed that the death of Abel took place in the one hundred and twenty-eighth or one hundred and twenty-ninth year of the world. Now, "supposing Adam and Eve to have had no other sons than Cain and Abel in the year of the world one hundred and twenty-eight, yet as they had daughters married to these sons, their descendants would make a considerable figure on the earth. Supposing them to have been married in the nineteenth year of the world, they might easily have had each eight children, some males and some females, in the twenty-fifth year. In the fiftieth year there might proceed from them in a direct line sixty-four persons; in the seventy-fourth year there would be five hundred and twelve; in the ninety-eighth year, four thousand and ninety-six; in the one hundred and twenty-second they would amount to thirty-two thousand seven hundred and sixty-eight: if to these we add the other children descended from Cain and Abel, their children, and their children's children, we shall have, in the aforesaid one hundred and twenty-eight years four hundred and twenty-one thousand one hundred and sixty-four men capable of generation, without reckoning the women either old or young, or such as are under the age of seventeen." See Dodd. But this calculation may be disputed, because there is no evidence that the antediluvian patriarchs began to have children before they were sixty-five years of age. Now, supposing that Adam at one hundred and thirty years of age had one hundred and thirty children, which is quite possible, and each of these a child at sixty-five years of age, and one in each successive year, the whole, in the one hundred and thirtieth year of the world, would amount to one thousand two hundred and nineteen persons; a number sufficient to found several villages, and to excite the apprehensions under which Cain appeared at this time to labor.

Adam Clarke, 1831 · public domain