4:19-24 One of Cain's wicked race is the first recorded, as having broken the law of marriage. Hitherto, one man had but one wife at a time; but Lamech took two. Wordly things, are the only things that carnal, wicked people set their hearts upon, and are most clever and industrious about. So it was with this race of Cain. Here was a father of shepherds, and a father of musicians, but not a father of the faithful. Here is one to teach about brass and iron, but none to teach the good knowledge of the Lord: here are devices how to be rich, and how to be mighty, and how to be merry; but nothing of God, of his fear and service. Present things fill the heads of most. Lamech had enemies, whom he had provoked. He draws a comparison betwixt himself and his ancestor Cain; and flatters himself that he is much less criminal. He seems to abuse the patience of God in sparing Cain, into an encouragement to expect that he may sin unpunished.
If Cain shall be avenged sevenfold, truly Lamech seventy and sevenfold. Which if understood of him as confessing and lamenting his sin of murder, the sense is, if Cain was so severely punished for killing one man, of how much sorer punishment am I deserving, and shall have, who have killed two persons, and that after I had seen the punishment of Cain, and yet took no warning by it? or if he that killed Cain, who slew his brother, was to be avenged sevenfold, or to seven generations, then how much more, or longer, shall he be avenged, that shall slay me, who have slain none, or however not designedly; and therefore you may be easy and quiet, your fears, either from God or man, are groundless.