Albert Barnes Commentary Jeremiah 11:6

"And Jehovah said unto me, Proclaim all these words in the cities of Judah, and in the streets of Jerusalem, saying, Hear ye the words of this covenant, and do them." — Jeremiah 11:6 (ASV)

Proclaim ... - Probably Jeremiah accompanied Josiah in his progress (2 Kings 23:15–20), and everywhere read to the people the words of the newly-found book.