In the day that thou stoodest on the other side, in the day that the strangers carried away captive his forces, and foreigners entered into his gates, and cast lots upon Jerusalem, even thou wast as one of them.
In the day that thou stoodest on the other side - in an attitude of hostility, rather than exhibiting the sympathy which became a brother, feasting thine eyes (see Obadiah 1:12) with the misery of Jacob, and eagerly watching for his destruction. So Messiah, the antitype to Jerusalem, abandoned by His kinsmen (Psalms 38:11).
In the day that the strangers - the Philistines; the Arabians in the reign of Jehoram, king of Judah, etc. (2 Chronicles 21:16); the Syrians in the reign of Joash of Judah (2 Chronicles 24:24); the Chaldeans under Nebuchadnezzar (2 Chronicles 36:1-23).
Carried away captive his forces - his "host" (Obadiah 1:20); the multitude of Jerusalem's inhabitants.
And cast lots upon Jerusalem - (Joel 3:3). So Messiah, Jerusalem's antitype, had his only earthly possessions cast lots for (Psalms 22:18).
Even thou wast as one of them. There is no "wast" in the Hebrew, 'Thou, too, as one of them!' Edom was not one of them, an alien to Jacob or Israel: nay, he was his twin brother. The prophet graphically sets before himself and us Edom among the plunderers of Jerusalem, and exclaims, marveling at the unnatural sight, 'What, thou too AS one of them!