Behold, therefore I will bring strangers upon thee, the terrible of the nations: and they shall draw their swords against the beauty of thy wisdom, and they shall defile thy brightness.
Therefore - apodosis or consequent member of the sentence; the protasis or antecedent member is in Ezekiel 28:2; Ezekiel 28:6.
I will bring strangers upon thee, the terrible of the nations - the Chaldean foreigners, noted for their ferocity (Ezekiel 30:11; Ezekiel 31:12).
They shall draw their swords against the beauty of thy wisdom - i:e., against thy beautiful possessions, acquired by thy wisdom, on which thou so pridest thyself (Ezekiel 28:3-5).
They shall defile thy brightness - i:e., obscure the brightness of thy kingdom.