17 Cain had sexual relations with his wife, and she became pregnant and gave birth to Enoch. Then Cain founded a city, which he named Enoch, after his son. 18 Enoch had a son named Irad. Irad became the father of Mehujael. Mehujael became the father of Methushael. Methushael became the father of Lamech.
19 Lamech married two women. The first was named Adah, and the second was Zillah. 20 Adah gave birth to Jabal, who was the first of those who raise livestock and live in tents.
Matthew Henry's Commentary on Genesis 4:17-20
Commentary on Genesis 4:16-18
(Read Genesis 4:16-18)
Cain cast off all fear of God, and attended no more on God's ordinances. Hypocritical professors, who dissemble and trifle with God, are justly left to themselves to do something grossly scandalous. So they throw off that form of godliness to which they have been a reproach, and of which they deny the power. Cain went out from the presence of the Lord, and we never find that he came into it again, to his comfort. The land Cain dwelt in was called the land of Nod, which means, 'shaking,' or 'trembling,' and so shows the restlessness and uneasiness of his own spirit, or 'the land of a vagabond:' they that depart from God cannot find rest any where else. Those on earth who looked for the heavenly city, chose to dwell in tabernacles or tents; but Cain, as not minding that city, built one on earth. Thus all who are cursed of God seek their settlement and satisfaction here below.
Commentary on Genesis 4:19-24
(Read Genesis 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.