Or HaChaim on Deuteronomy 2:8/אור החיים על דברים ב׳:ח׳

1 ונעבר מאת אחינו בני עשו, "we passed by from our brethren the children of Esau, etc." The reason Moses stresses the brotherly relations with Esau is to remind the Israelites that the Jewish people had abided by G'd's command not to cause any friction or provocation in their dealings with the Edomites. Another reason why Moses refers to them as "our brothers" was because they maintained correct relations with the Israelites, selling them whatever produce the Israelites were willing to buy. We know this from verse 29 in our chapter.