What does Deuteronomy 2:4 mean?

'Give the people this message: You’re about to pass through the territory of your relatives, the descendants of Esau, who live in Seir. They’ll be afraid of you, so be very careful.' Deuteronomy 2:4 - Modern Text Bible

(God warned them to be cautious and respectful as they passed through Edom, their relatives’ land.)