The LORD told me, “Don't try to start a war with Moab. Leave them alone, because I gave the land of Ar to them, and I will not let you have any of it.”
You can see that the armies of Ammon, Moab, and Edom are attacking us! Those are the nations you would not let our ancestors invade on their way from Egypt, so these nations were not destroyed.
They sent messengers to the king of Edom and said, “Please, let us go through your country.” But the king of Edom refused. They also sent messengers to the king of Moab, but he wouldn't let them cross his country either. And so the Israelites stayed at Kadesh.
A little later, the Israelites set out into the desert, going east of Edom and Moab, and camping on the eastern side of the gorge of the River Arnon. The Arnon is the eastern border of Moab, and since the Israelites didn't cross it, they didn't even set foot in Moab.