Their Redeemer is strong; the LORD of hosts is his name. He will surely plead their cause, that he may give rest to the earth, but unrest to the inhabitants of Babylon.
But he immediately after removes this ground of despair, and says, Their redeemer is strong He then sets this strong, חזק, chesek, in opposition to the verb used before, “prevailed” or ruled, החזיקו בם, echesiku beem, “prevailed” or domineered “over them,” so that they were stronger.
We have in these verses, I. Israel's sufferings, and their deliverance out of those sufferings. God takes notice of the bondage of his people in Babylon, as he did of their bondage in Egypt; he has surely seen it, and has heard their cry. Israel and Judah were oppressed together, Jer 50:33.
Commenting on Jeremiah 50:33-46
Their Redeemer is strong, the Lord of hosts is his name,.... And seeing his name is the Lord of hosts or armies, and has all the armies of heaven and earth at his command; and especially since he is Jehovah, the everlasting and unchangeable I AM; he must be strong and mighty, yea, the Almighty, and so able to redeem his Israel, as the Messiah...