147. Who can doubt, moreover, that Satan by this new species of temptation increased greatly the grief of our first parents? They no doubt thought, Behold, this is all our sin. We, in paradise, wished to become like God; but by our sin we have become like the devil. This is the case also with our son. We loved only this son, and made everything of him! Our other son, Abel, was righteous before us, above this son; but of his righteousness we made nothing! This elder son we hoped would be he who should crush the serpent's head; but behold, he himself is crushed by the serpent! Nay, he himself has become like the serpent, for he is now a murderer. And whence is this? Is it not because he was born of us, and because we, through our sin, are what we are? Therefore it is to our flesh; therefore it is to our sin, that this calamity must be traced.
148. It is very probable, accordingly, and the events of the series of years which followed strengthen this probability, that the sorrowing parents, shaken to the core by their calamity, abstained for a long time from connubial intercourse. For it appears that when Cain committed this murder he was about thirty years of age. During this period some daughters were born unto Adam. In view of the subsequent statements, verse 17, that "Cain knew his wife," he no doubt married a sister. Moreover, since Cain himself says in verse 14, "It shall come to pass that everyone that findeth me shall slay me", and as it is further said in verse 15, "The Lord set a mark upon Cain, lest any finding him should kill him"—it appears most probable from all these circumstances that Adam had many children besides Cain and Abel, but these two only are mentioned, on account of their important and memorable history, and because these two were their first and most remarkable children. It is my full belief that the marriage of our first parents was most fruitful during the first thirty years of their union. Somewhere Calmana and Dibora are mentioned as daughters of Adam, but I know not whether the authors are worthy of credence. Inasmuch, therefore, as the birth of Seth is recorded as having taken place a long time after this murder, it seems to me very probable that the parents, distressed beyond measure at this monstrous crime in the bosom of their family, refrained for a long time from procreation. While Moses does not touch upon all these things, he intimates enough to arouse in the reader a desire to dwell upon the noteworthy events which the absence of detailed information permits us to survey only from a distance.
149. But I return to the text before us. Cain is an evil and wicked man, and yet, in the eyes of his parents, he is a divine possession and gift. Abel, on the contrary, is in the eyes of his parents nothing; but in the eyes of God he is truly a righteous man; an appellation with which also Christ honors him when he calls him "righteous Abel"! Mt 23, 35. This divine judgment concerning Abel, Cain could not endure, and, therefore, he thought that by murder not only the hatred against his brother could be satisfied, but also his birthright be retained. But he was far from thinking that was sin; as the first-born he thought he had exercised his right. He killed Abel, not with a sword, as I think, but with a club or a stone, for I hold that there were as yet no iron weapons.
150. After the murder, Cain remained unconcerned, for he thought the deed could be concealed by hiding the body, which he buried, or perhaps cast into a river, thinking that thus it would surely remain undiscovered by his parents.
When Abel, however, had been from home a longer time than had been his habit, the Holy Spirit prompted Adam to inquire of Cain concerning Abel, saying, "Where is Abel thy brother?" The above-mentioned utterance of Adam, "If not, sin lieth at the door," was a prophecy which now began to come true. Cain thought he had laid his sin to rest, and all would thus remain hidden. And true it was that his sin did lie at rest, but it lay at rest "at the door." And who opens the door? None other than the Lord himself! He arouses the sleeping sin! He brings the hidden sin to light!
151. The same thing must come to pass with all sinners. For, unless by repentance you first come to God, and yourself confess your sin to God, God will surely come to you, to disclose your sin. For God cannot endure that any one should deny his sin. To this fact the psalmist testifies: "When I kept silence, my bones wasted away through my roaring all the day long. For day and night thy hand was heavy upon me; my moisture was changed as with the drouth of summer." Ps 32, 3-4. For, although sin has its sleep and its security, yet that sleep is "at the door"; it cannot long last, and the sin cannot remain hidden.