Genesis 32:3

32:3 Jacob sent messengers on ahead to his brother Esau in the land of Seir, the region of Edom.

Genesis 36:8

36:8 So Esau (also known as Edom) lived in the hill country of Seir.

Deuteronomy 2:5

2:5 Do not be hostile toward them, because I am not giving you any of their land, not even a footprint, for I have given Mount Seir as an inheritance for Esau.