Thus saith the Lord GOD; Because that Moab and Seir do say, Behold, the house of Judah is like unto all the heathen;
Because that Moab and Seir do say. Moab, Seir, and Ammon were contiguous countries, stretching in one line from Gilead on the north to the Red Sea. They therefore naturally acted in concert, and in joint hostility to Judea.
Judah is like unto all the heathen. The Jews fare no better than others: it is of no use to them to serve Yahweh, who, they say, is the only true God.