Jeremiah 46:28
Fear thou not, O Jacob my servant, saith the LORD: for I am with thee; for I will make a full end of all the nations whither I have driven thee: but I will not make a full end of thee, but correct thee in measure; yet will I not leave thee wholly unpunished.
Jeremiah 46:28 stands in Jeremiah 46 to 51, which give prophecies against foreign nations, especially Babylon. Within that section it falls among the prophecies against Egypt and other nations. That section gives particular attention to Babylon, whose ancient empire is presented as a type of mystical Babylon.
It belongs to the prophecy describing the revolutions and future state of Egypt. That prophecy foretells Egypt's invasion, conquest, spoiling and subjection to strangers by Nebuchadnezzar king of Babylon. It has been fulfilled through more than twenty-four centuries of history as an evidence of Christianity. The verse teaches that God is with Jacob and will preserve him, while correcting him in measured judgment and not leaving him wholly unpunished. God will make a full end of all the nations whither He drove His people, but He will not make a full end of His people.
God Himself will gather Israel and save Jacob from afar off and his seed from the land of captivity. He will bring Jacob to return and be in rest and at ease with none to make him afraid. This means Israel will not gather themselves and rebuild Jerusalem by their own action, but God will do the gathering. The verse is part of the prophecies concerning restoration from Babylon and points beyond that restoration to the more glorious restoration under Christ. The book's assurances of God's kindness and everlasting love, along with its warnings and appeals, are applicable to the present day.
For those who follow Christ, the verse shows that God disciplines with measured correction while still holding them accountable. Christians must therefore not expect a smooth life on earth, but crosses that are unpleasant yet beneficial. Those crosses are chosen for them by a good and wise God contrary to their own desires, and are approved by them afterward. Murmuring against God is murmuring against their own good. The number and kind of those crosses were fixed when their names were written in His book.