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.
19. Lamech took unto him two wives—This is the first transgression of the law of marriage on record, and the practice of polygamy, like all other breaches of God's institutions, has been a fruitful source of corruption and misery.