J. N. Darby · The spirit of the book:

The Book of the Prophet Jeremiah has a different character from that of Isaiah. It does not contain the same development of the counsels of God respecting this earth that Isaiah does. It is we, that we are told many things in it concerning the nations; but it is principally composed of testimony addressed immediately to the conscience of the people, on the subject of their moral condition at the time the prophet speaks, and with an eye to the judgment with which they were threatened. Judah had forsaken Jehovah; for their repentance under Josiah was but a fair appearance, and under the kings that succeeded him their degradation was complete. The prophet's heart was overwhelmed with grief, because of his love for the people; at the same time that he was filled with a deep sense of their relationship with the Lord. The sense of this produced a continual conflict in his soul between the thought of the value of the people as the people of God, and a holy jealousy for the glory of God and His rights over His people — rights which they were trampling under foot. This was an incurable wound to his heart. He had pleaded for the people, he had stood in the breach for them before Jehovah; but he saw that it was all in vain: the people rejected God and the testimony that He sent them. God Himself would no longer hearken to prayer made for Israel. Jeremiah prophesies under this impression: a sorrowful task, indeed, and one which made the prophet truly a man of sorrow. And although he could always say that, if the people repented, they would be received in grace, he well knew that the people had even no thought of repenting. Two things sustained him in this painful service: (for what could be more painful than to announce judgment for their iniquities, to a people beloved of God?) first of all, the energy of the Spirit of God, which filled his heart and compelled him to announce the judgment of God, in spite of contradiction and persecution; and then the revelation of the people's final blessing according to the unchangeable counsels of God. After this brief notice of the spirit of the Book of Jeremiah, the proofs and details of which we shall find in going through his prophecies, let us now examine these in succession.