Комментарий к Ирмеяу 6:29

The bellows is heated This is an allegory. When they refine silver, they blow with a bellows, and they always put lead into the crucible, which helps for the refining. But you—I have come to refine you. The bellows is heated and parched because of the fire, and the lead is completely consumed. נחר is an expression related to (Job 42:7) “My wrath has been kindled (חרה)”; (ibid. 30:30) “And my bones are burned (חרה) with heat,” (esrast in O.F.).

in vain In vain does the founder refine, for it is of no avail

and the wicked ones have not been separated from their evil way. That is to say that the prophets toiled to reprove, but it did not avail them.