Faithfulness to the covenant with Yahweh is the theme here. A covenant promise cannot be broken because it is an oath taken before Yahweh (34:15). A violation of the covenant, therefore, is an outright disregard for the sacredness of the divine name. Zedekiah and the citizens of Jerusalem renewed the Sinai covenant and demonstrated their repentance during the siege of the city by Babylon only to break it when the crisis was over. This was typical of the unfaithfulness that was a characteristic of Israel for many generations. Therefore they are under the curse of the covenant. In ch. 35 Jeremiah contrasts the unfaithfulness of the nation with the faithfulness of the Rechabites to the command of their ancestor Jonadab (v. 14). The Rechabites' refusal to yield to any pressure from others and to compromise their ideals is a lesson from which Judah must learn the meaning of fidelity to their covenant obligation to Yahweh. Because they obey their forefather's command (v. 14) is the reason for the blessing pronounced upon the Rechabites (v. 19).
Consult other commentaries on the significance of ch. 36 to our understanding of the composition of the book of Jeremiah. The primary goal of God's spoken and written word is to lead each listener to repentance, which is a necessary condition for the experience of forgiveness by him (36:3; see also 35:15). On a publicly declared day of fast, a day set aside for prayer and penitence, King Jehoiakim was not only unmoved but also acted in defiance of Yahweh's written word, which was read to him on such a solemn occasion (vv. 9, 22-25). Rejection of Yahweh's word is rejection of his sovereign authority. Judgment is the final word upon the house of Jehoiakim who refused to listen to the spoken and the written word of Yahweh (vv. 30-31).
Chs. 37 and 38 contrast Jeremiah with King Zedekiah. Jeremiah is Yahweh's spokesman, but Zedekiah has not paid any attention to the words the Lord has spoken (37:2). Zedekiah is indirect in his approach to Jeremiah with the request to pray on behalf of the nation, but Jeremiah is direct and straightforward in declaring the coming catastrophe (vv. 3-10). Zedekiah is weak, indecisive, and fearful of his court officials, but Jeremiah, though he is falsely accused, mistreated, and imprisoned, is firm and unafraid to speak to the king about his fate (vv. 11-17; 38:1-6; 14-28). Jeremiah understands clearly what is morally right and wrong, but Zedekiah lacks a clear perception of right and wrong (37:18; 38:5). Ironically, Zedekiah (“Yahweh is my righteousness”) learns a lesson on righteousness by Ebed-Melech, a gentile servant of the court (38:1-13). Jeremiah exemplifies a tenacious faith in God. Zedekiah, though he seeks to learn God's plan for Judah, ends up rejecting not only the prophetic counsel, but also the promise of life given to him (a special grace) in the final hour of Judah's history (vv. 17-23). Zedekiah demands that Jeremiah disclose everything that he received through revelation (37:14), yet to protect his own personal interest he charges the prophet not to reveal the whole content of his conversation to the court officials (vv. 24-27). Jeremiah yields to the wishes of the king despite his protest that the king will not listen (v. 15), and he remains true to his prophetic task as well as to his duty to the king. Clarke notes that the king was asking Jeremiah to tell “the truth, and nothing but the truth, but not the whole truth” and that Jeremiah was “most certainly not obliged to relate any thing” other than “what was necessary” to these officials (pp. 358-59).