Thomas Aquinas Commentary Jeremiah 27:16-19

"Also I spake to the priests and to all this people, saying, Thus saith Jehovah: Hearken not to the words of your prophets that prophesy unto you, saying, Behold, the vessels of Jehovah`s house shall now shortly be brought again from Babylon; for they prophesy a lie unto you. Hearken not unto them; serve the king of Babylon, and live: wherefore should this city become a desolation? But if they be prophets, and if the word of Jehovah be with them, let them now make intercession to Jehovah of hosts, that the vessels which are left in the house of Jehovah, and in the house of the king of Judah, and at Jerusalem, go not to Babylon. For thus saith Jehovah of hosts concerning the pillars, and concerning the sea, and concerning the bases, and concerning the residue of the vessels that are left in this city," — Jeremiah 27:16-19 (ASV)

^27:20 which Nebuchadnezzar, king of Babylon, did not take when he carried away Jeconiah, son of Jehoiakim, king of Judah, from Jerusalem to Babylon, along with all the nobles of Judah and Jerusalem.

Here the admonition is given to the priests and to the common people.

1. He refutes the false counsel: do not listen ... behold, the vessels, which were taken away to Babylon with Jeconiah (2 Kings 24:13–15). He gives the reason by exposing the prophets’ lie: for they prophesy a lie to you. He shows the benefit of submission, that you may live, and the danger of rebellion: why should this city be made a desolation? This is consistent with what was said before: he who goes out and surrenders to the Chaldeans who are besieging you will live (Jeremiah 21:9).
2. He asks for proof of their truthfulness: and if they are prophets. It is as if he is saying, “Let them accomplish the lesser task, so that they might be believed concerning the greater one.” Specifically, by praying to God, they should prevent the remaining vessels from being carried off. If they can do this, they might be believed about the greater claim that the vessels already taken will be brought back. You have not gone up against the enemy, nor have you set up a wall for the house of Israel, so that you may stand in battle on the day of the Lord (Ezekiel 13:5).
3. He proves their falsehood with an argument from the greater to the lesser: if the more likely event—that the remaining vessels will not be carried away—does not happen, then the less likely event—that the vessels already taken will be returned—certainly will not happen either. For thus says the LORD concerning the columns—the two Solomon made for the portico—and concerning the sea, and concerning their bases—the basin where water was kept for the priests’ washings, which was set upon twelve bases, all of which is described in 1 Kings 7.

He continues: for thus says the LORD, concerning the temple vessels that had not yet been taken, apart from those in the portico. The vessels of her glory were led into captivity . And he promises that they will be brought back in the future: and I will cause them to be brought back, in the time of Cyrus.

Cyrus the king brought out the sacred vessels of the Lord, which Nebuchadnezzar had taken from Jerusalem and consecrated to his idol. And bringing them out, Cyrus, king of the Persians, handed them over to Mithredath, who was in charge of his treasures, and by him they were given to Shalmanezar, the ruler of Judah (Ezra 1:7–8).