Deuteronomy 2:4

It would appear that the Edomites made preparations to resist the passage of the Israelites through their territory ( Numbers 20:18-20 ). As the Israelites, however, kept on the outskirts of their country, and did not attempt to penetrate into the interior, the Edomites did not attack them or seek to hinder their progress. The Israelites, on the other hand, were strictly forbidden to invade that country in a hostile manner; they were to watch over themselves, so as not to be tempted to make war on the Edomites, who were their brethren; as God would not give them any part, not so much as a foot-breadth, of that laud, for he had given Esau (i.e. the race descended from Esau, the Edomites— LXX , τοῖς υἱοῖς ησαῦ ) Mount Seir for a possession. They shall be afraid of you (see Exodus 15:15 ).