John Calvin Commentary Genesis 19:37

"And the first-born bare a son, and called his name Moab: the same is the father of the Moabites unto this day." — Genesis 19:37 (ASV)

And the firstborn bore. This was a terrible blindness: the daughters of Lot, shaking off all feeling of shame, raised up a memorial of their virtue and, through an eternal sign, exhibited their dishonor to their posterity. To their sons—or rather, to two nations in their persons—they gave names from which everyone could know that it was a family originating from adultery and unchaste intercourse.

The eldest boasts that she had obtained her son from her father; the other, that her son was born of a close relative. Thus, both unashamedly proclaimed their crime, when they should rather, out of shame for their crime, have hidden themselves in perpetual hiding places. Not content with their infamy in their own time, they propagated their crime to other times. Therefore, there is no doubt that they, enchanted by Satan, had forgotten all difference between what is scandalous and what is honorable.

Paul says (Romans 2:5), that the wicked, after long pleasure in sinning, are in the end deprived of all feeling of grief for it. Such senselessness undoubtedly had seized those girls, because they were not ashamed to spread their dishonor everywhere. Furthermore, such an example of God’s punishment is revealed to us so that we do not indulge any sin and do not lose ourselves in licentiousness, but instead, through the fear of God, spur ourselves on to repentance.

CHAPTER 20.