Jeremiah issues a sharp challenge to the false prophets who are promising the people a swift return of the Temple vessels already exiled to Babylon. Instead of spreading false hopes about what is already lost, he demands that they use their spiritual standing to confront the approaching danger and save the property still left in Jerusalem. He argues that if these men are indeed true prophets with a special connection to God, they must plead with Him right now. Rather than focusing on the treasures taken during the previous exile, they need to beg for mercy so that the remaining vessels in the Temple and the king's palace are not carried off to Babylon as well [מצודת דוד, מצודת ציון, ביאור שטיינזלץ, רד״ק].
This demand for prayer is not arbitrary; it is rooted in the fundamental role of a prophet. Jeremiah has already received a clear prophecy that the remaining vessels are destined for exile. If these men had genuinely received the word of God, they would have been exposed to this harsh decree as well. When God delivers a prophecy of disaster to a prophet as a private message, rather than as a public warning meant to inspire the people to repent, He does so with a specific purpose: to allow the prophet to pray and annul the decree. Therefore, Jeremiah tells them that if God has truly spoken to them, their immediate duty is to stand in prayer and stop the impending exile of the remaining vessels, because in such circumstances, prayer actually has the power to change the outcome [מלבי״ם].