There is some disputes amongst interpreters, whether the words here, Merathaim and Pekod, be to be taken as common nouns, the one signifying rebels or rulers, the other visitation, because the Chaldeans were rebels against the Lord, and were great rulers over all the contiguous nations; or whether they be proper names of some places which Cyrus passed by, or, it may be, took in, and conquered in his way to Babylon. The latter are God's words by his prophet, like the former, commanding him with his armies to go up and destroy them fleeing away, or them that should succeed after them, their whole posterity; intimating God's design utterly to destroy them, which destruction was gently begun by Cyrus, and perfected by Darius.
Related Commentaries of Jeremiah 50:21
Jeremiah 50:21
21 Go up against the land of Merathaim,f even against it, and against the inhabitants of Pekod: waste and utterly destroy after them, saith the LORD, and do according to all that I have commanded thee.