Albert Barnes Commentary Jeremiah 50:9

"For, lo, I will stir up and cause to come up against Babylon a company of great nations from the north country; and they shall set themselves in array against her; from thence she shall be taken: their arrows shall be as of an expert mighty man; none shall return in vain." — Jeremiah 50:9 (ASV)

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, that is, by the great nations coming from there.

Return in vain - A proverbial expression for ill success . Here the skillful warrior returns not empty.