Numbers 24:18

24:18 Edom will be a possession,

Seir, ¹  his enemies, will also be a possession;

but Israel will act valiantly.

Numbers 32:21

32:21 and if all your armed men cross the Jordan before the Lord until he drives out his enemies from his presence

[24:18]  ¹ sn Seir is the chief mountain range of Edom (Deut 33:2), and so the reference here is to the general area of Edom.