What does 2 Chronicles 20:10 mean?

Now, look—here come the people from Ammon, Moab, and Mount Seir. You didn’t let Israel invade them when we left Egypt, so we avoided them and didn’t destroy them. 2 Chronicles 20:10 - Modern Text Bible

(The speaker points out that these nations were spared by Israel in the past, following God's instructions, but now they are the ones threatening Israel.)