Deuteronomy 2:37
Only unto the land of the children of Ammon thou camest not, nor unto any place of the river Jabbok, nor unto the cities in the mountains, nor unto whatsoever the LORD our God forbad us. Only unto the land of the children of Ammon thou camest not, nor unto any place of the river Jabbok, nor unto the cities in the mountains, nor unto whatsoever the LORD our God forbad us.
On the northward march toward the promised land, after passing to the south of Edom and crossing the brook Zered, Israel passed to the east of the land of Moab rather than taking Ar for a possession. The verse records that Israel came not to the land of the children of Ammon, nor to any place of the river Jabbok, nor to the cities in the mountains, nor to whatsoever the Lord God had forbidden. Israel stayed out because God had given the same direction concerning the Ammonites as concerning the Moabites, not to distress them and not to contend with them in battle. Both peoples were spared because they were descendants of Lot.
The account illustrates obedience to God's commands by respecting the boundaries and places He forbade, in a chapter that sets forth blessings for obedience and warnings against disobedience.