Israel was to undertake war only with the purpose of dispossessing former inhabitants of the area the Lord had promised them; Edom was not part of that area, and so the Lord forbade his people from engaging them in war. He had instead given Edom to Esau for a possession. God held power over peoples and nations in addition to Israel.
5 Ne les attaquez pas; car je ne vous donnerai dans leur pays pas même de quoi poser la plante du pied: j'ai donné la montagne de Séir en propriété à Esaü.