Charles Ellicott Commentary 2 Kings 24:12

"and Jehoiachin the king of Judah went out to the king of Babylon, he, and his mother, and his servants, and his princes, and his officers: and the king of Babylon took him in the eighth year of his reign." — 2 Kings 24:12 (ASV)

And Jehoiaehin the king of Judah went out ... —Despairing of the defense, he threw himself upon the clemency of Nebuchadnezzar. The queen-mother (Jeremiah 22:2) and all his grandees and courtiers accompanied the king, who probably hoped to be allowed to keep his throne as a vassal of Babylon.

Took him —that is, as a prisoner.

In the eighth year of his (that is, Nebuchadnezzar’s) reign. —This exactly tallies with the data of Jeremiah 25:1; Jeremiah 46:2.