פּירוש אויף עובדיה 1:11

On the day you stood from afar—that you did not come to aid him.

you, too, are like one of them—I account it for you as though you were one of their attackers.

“On the day that you stood aside, on the day when foreigners carried off” [1:11]. When the evil Titus came against Israel and Jerusalem, Edom rejoiced and also stood on the side to insult Israel and gave Israel into the hands of the people from the city of Rome. You Edom should have helped Israel, since they are your brothers. The Holy One had forbidden in the desert, with Moses our Teacher, that Israel should not do any evil acts to Edom because they are your brothers. During the destruction of Jerusalem, Edom did not think about this brotherhood.⁶Radak, Obadiah, 1:11.