Jeremiah 52:26 describes how Nebuzaradan, the captain of the Babylonian guard, took certain people and brought them to the king of Babylon at a place called Riblah. This verse records an event during the Babylonian conquest of Jerusalem, when important captives were taken to face the Babylonian king.
The setting is the aftermath of Jerusalem’s fall in 586 BCE. The verse is part of a historical account, not a speech or prophecy, and simply reports what happened: Nebuzaradan, a high-ranking Babylonian official, gathered prisoners and transported them to Riblah, where the Babylonian king was stationed. This action was a step in the process of judgment and exile for the leaders and officials of Judah.