Deuteronomy 2:16 - 19

"Now when the last of these fighting men among the people had died, the Lord said to me, 'Today you are to pass by the region of Moab at Ar. When you come to the Ammonites, do not harass them or provoke them to war, for I will not give you possession of any land belonging to the Ammonites. I have given it as a possession to the descendants of Lot.'" NIV translation

Once again, Moses reminds the people that they had passed through the land of their relatives the Ammonites. They had not fought there because it was not a part of their promised land. The Ammonites were relatives because they were descended from the relationship between Lot and his daughter.

Deuteronomy 2:20 & 21

"(That too was considered a land of the Rephaites, who used to live there; but the Ammonites called them Zamzummites. They were a people strong and numerous, and as tall as the Anakites. The Lord destroyed them from before the Ammonites, who drove them out and settled in their place." NIV translation

Moses reminds the people that God had cleared the land of its giants and given it as an inheritance to Lots' descendants. That is a reminder to us, as Christians, that we all have our different giants to face but God will handle them all.