Charles Ellicott Commentary Genesis 19:31

"And the first-born 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:" — Genesis 19:31 (ASV)

The firstborn said to 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.