Commentary on the Bible, by Adam Clarke, , at sacred-texts.com
By the significant type of breaking a potter's vessel, Jeremiah is directed to predict the utter desolation of Judah and Jerusalem, Jer 19:1-15. The prophets taught frequently by symbolic actions as well as by words.
Go and get a potter's earthen bottle - This discourse was also delivered some time in the reign of Jehoiakim. Under the type of breaking a potter's earthen bottle or jug, Jeremiah shows his enemies that the word of the Lord should stand, that Jerusalem should be taken and sacked, and they all carried into captivity.
Ancients of the priests - The chiefs of the twenty-four classes which David had established. See Ch1 24:4.
Estranged this place - Ye have devoted my temple to a widely different purpose from that for which it was erected.
Offerings unto Baal - A general name for all the popular idols; Baal, Moloch, Ashtaroth, etc.
I will make void the counsel of Judah - Probably this refers to some determination made to proclaim themselves independent, and pay no more tribute to the Chaldeans.
To be meat for the fowls - See on Jer 7:33 (note).
I will cause them to eat the flesh of their sons - This was literally fulfilled when Jerusalem was besieged by the Romans. This also the prophet might have had in view.
Even so will I break this people and this city - The breaking of the bottle was the symbolical representation of the destruction of the city and of the state.
That cannot be made whole again - This seems to refer rather to the final destruction of Jerusalem by the Romans, than to what was done by the Chaldeans. Jerusalem was healed after 70 years: but nearly 1800 years have elapsed since Jerusalem was taken and destroyed by the Romans; and it was then so broken, that it could not be made whole again.
And even make this city as Tophet - A place of slaughter and destruction.
Then came Jeremiah from Tophet - He had probably gone to the valley of Hinnom, and there repeated the discourse which he had a little before delivered to the chief priests and elders.
Because they have hardened their necks - A metaphor taken from unruly and unbroken oxen, who resist the yoke, break and run away with their gears. So this people had broken and destroyed the yoke of the law.