The firstborn said unto the Younger. — Several modern commentators see in this recital a mark of Jewish hatred towards the Moabites and Ammonites, and an attempt to brand their origin with shame. Really we find in Deuteronomy 2:9-19, no trace of the existence of this hostility, but, on the contrary, the relationship of these two nations to Israel is used as a ground for kindly feelings; and in the story of Ruth the Moabitess, and the friendship which existed between the king of Moab and David, we have proof that such feelings existed.
Related Commentaries of Genesis 19:31
Genesis 19:31
31 And the firstborn said unto the younger, Our father is old, and there is not a man in the earth to come in unto us after the manner of all the earth: