Jeremiah 52:20
The two pillars, one sea, and twelve brasen bulls that were under the bases, which king Solomon had made in the house of the LORD: the brass of all these vessels was without weight. The two pillars, one sea, and twelve brasen bulls that were under the bases, which king Solomon had made in the house of the LORD: the brass of all these vessels was without weight.
The inventory names the two pillars, the single sea, and the twelve bronze bulls that stood under the bases, all of which Solomon had fashioned for the house of the Lord. The bronze in all these vessels was beyond weighing, meaning its amount was so immense that it could not be measured. This reckoning belongs to the account of Jerusalem's destruction and the carrying away of the surviving sanctuary vessels to Babylon.
The wider chapter records that God brought that destruction upon Jerusalem because the people would not listen and keep the Sabbath holy. The warning stood that if they bore no burdens on the Sabbath day then Jerusalem would stand forever, but if they would not hearken God would destroy it, and the fall fulfilled that word. In the same setting the record of the unweighed bronze stands among Jeremiah's lessons concerning Babylon's doom. It serves as a warning to cities that forget and defy God.