Adam Clarke on Jeremiah 30:1

The word that came to Jeremiah from the Lord - This prophecy was delivered about a year after the taking of Jerusalem; so Dahler. Dr. Blayney supposes it and the following chapter to refer to the future restoration of both Jews and Israelites in the times of the Gospel; though also touching at the restoration from the Babylonish captivity, at the end of seventy years. Supposing these two chapters to be penned after the taking of Jerusalem, which appears the most natural, they will refer to the same events, one captivity shadowing forth another, and one restoration being the type or pledge of the second.