An assembly of great nations - The army of Cyrus was composed of Medes, Persians, Armenians, Caducians, Sacae, etc. Though all these did not come from the north; yet they were arranged under the Medes, who did come from the north, in reference to Babylon.
Their arrows - They are such expert archers, that they shall never miss their mark.
I will raise - Or, stir up.
An assembly of great nations - The Medo-Persian empire was as much an aggregate of discordant nations as that of Babylon.
From thence - From the north, i. e., by the great nations coming thence.
Return in vain - A proverbial expression for ill success (compare Isaiah 55:11). Here the skillful warrior returns not empty.