Jeremiah's prophecy concerning all the people of Judah includes three things. First, in verses 3 through 11 Jeremiah prophesied that because Israel did not listen to the prophets to turn from her evil way, Jehovah would send from the north Nebuchadnezzar, the king of Babylon, to attack Israel and make her an astonishment, a hissing, and an eternal reproach. Jeremiah also prophesied that Israel would serve the king of Babylon seventy years.
Second, Jeremiah prophesied that after the seventy years Jehovah would punish the king of Babylon and make the nation of Babylon an eternal desolation (vv. 12-14).
Finally, here Jeremiah prophesied that Jehovah would also punish all the nations of the earth beginning from Israel, until all the inhabitants of the earth would be slain by Jehovah (vv. 15-38).
Jeremiah 26 records the reaction of the people of Judah to Jeremiah's prophecy concerning their destiny.
In the first seven verses of chapter twenty-six, we have Jeremiah's prophecy.
The word of this prophecy was given to Jeremiah in the beginning of the reign of Jehoiakim the son of Josiah, king of Judah (v. 1).
Jehovah charged Jeremiah to stand in the court of the house of Jehovah and speak to all the cities of Judah, who came to worship in the house of Jehovah (v. 2). When the people came to worship in the temple, Jeremiah was to take that as an opportunity to prophesy to them.