The fourth generation. — Heb., dôr. (See Note on Genesis 6:9.) As the four generations are identical with the four centuries of Genesis 15:13, we have here an undesigned testimony to the long duration of human life. So Abram was 100 years old when Isaac was born, and Isaac was 60 at the birth of his children, and Jacob 64 years of age at his marriage. But the word dôr had probably come down from a remote antiquity, and, like the Latin word seculum, signified a century.
The iniquity of the Amorites. — As the chief and leading tribe, they are used here for all the Canaanite nations. We learn from this declaration that the Canaanites were not extirpated by any wilful decree to make room for Israel, but as an act of justice, like that which, because of their moral depravity, overwhelmed the Sethites with a flood. So, subsequently, Israel and Judah had each to bear a punishment in accordance with their sinfulness; and so, throughout the history of the world, whenever nations settle down in vice and corruption, the decay of their institutions follows upon that of their morals, and they either waste away or give place to some more manly race of conquerors. The conquest of Canaan by Israel was parallel to that of the enervated Roman empire of the West by the Germans; only we see the preparation for it. and God’s purpose explained; and we also see that if the Amorites had not made the scale of justice weigh down heavily, they would not have been deprived of their country.