Charles Ellicott Commentary Jeremiah 26:12

"Then spake Jeremiah unto all the princes and to all the people, saying, Jehovah sent me to prophesy against this house and against this city all the words that ye have heard." — Jeremiah 26:12 (ASV)

The Lord sent me to prophesy ... —The answer of the accused is that of all true prophets and preachers of the word, The Lord God has spoken, and he can but prophesy (Amos 3:8). He must obey God rather than man (Acts 5:29). And in this instance the prophet has nothing in the way of credentials but the message itself. He worked no signs or wonders.