I will rejoice in doing them good is more literally “I will rejoice upon them to do good [to] them.” The verb rejoice is found only here in Jeremiah, though it is prominent in Isaiah (35.1 [Revised Standard Version “be glad”]; 61.10; 62.5; 64.5 [Revised Standard Version “joyfully”]; 65.18 [Revised Standard Version “be glad”], 19 [Revised Standard Version “be glad”]; 66.10, 14).

I will plant them: See 1.10; 24.6.

In faithfulness: The meaning is “firmly” (Jerusalem Bible, New American Bible), “permanently” (Good News Translation, Die Bibel im heutigen Deutsch), or “truly” (Traduction œcuménique de la Bible). Elsewhere in Jeremiah this same construction is found in 4.2 (Revised Standard Version “in truth”); 26.15 (Revised Standard Version “in truth”); and 28.9 (Revised Standard Version “truly”).

With all my heart and all my soul: This information was evidently unintentionally omitted by Good News Translation. Die Bibel im heutigen Deutsch has “with my entire heart and full strength,” while Traduction œcuménique de la Bible has “with all my heart and all my being.” In Hebrew psychology these two terms would be a comprehensive expression of a person’s total being.

Quoted with permission from Newman, Barclay M. and Stine, Philip C. A Handbook on Jeremiah. (UBS Helps for Translators). New York: UBS, 2003. For this and other handbooks for translators see here .