Charles Ellicott Commentary Jeremiah 23:21

"I sent not these prophets, yet they ran: I spake not unto them, yet they prophesied." — Jeremiah 23:21 (ASV)

Yet they ran. —The image is that of messengers who rush eagerly, as from the king’s council-chamber, on their self-appointed mission, without waiting for the command of the Master in whose name they profess to come. (Compare the question, “Who will go for us?” in Isaiah 6:8.)