Deuteronomy 2:29 (ESV)

29 as the sons of Esau who live in Seir and the Moabites who live in Ar did for me, until I go over the Jordan into the land that the LORD our God is giving to us.’

The messengers were to stress in two ways Israel's good intentions. First, they were to say that Israel had previously passed through Seir and Moab in a peaceful manner. Second. they were to communicate that the destination was not the Amorite territory, but beyond the Jordan.