Jeremiah 25:2-3

Which Jeremiah spake to all the people of Judah That is, the word which he spake concerned them all, and he spake it to as many of them as he met with in any public assembly at Jerusalem or elsewhere. From the thirteenth year of Josiah In which year, as we read, Jeremiah 1:2, Jeremiah began to prophesy; Josiah reigned thirty-one years, 2 Kings 22:1; so that, taking in the thirteenth year, he prophesied nineteen years during the life of Josiah, to which the four years of Jehoiakim's reign being added, make the number twenty-three. These twenty-three years, says the prophet, I have been a preacher to you, and I have not been negligent in my work, but, like men that rise early in the morning to despatch their business, I have been attentive and laborious in the discharge of my prophetic office.