Jeremiah 19 - G. Campbell Morgan's Exposition on the Whole Bible

Jeremiah was now commissioned to go forth into the valley of the son of Hinnon, taking with him a potter's vessel. His message there was of judgment. Because the people had forsaken Jehovah, and had set up the most fearful abominations, even to the burning of their own sons in the fire, therefore judgment was determined against them.

This declaration of judgment Jeremiah was commanded to emphasize by breaking the vessel in the sight of the people, and declaring that in like manner Jehovah would break the people, and the city. Returning from Topheth, having obeyed this command, he stood in the court of the Lord's house and repeated the declaration of coming judgment.