You shall say to them repeats the information of verse 2 (“speak to … of Jerusalem”).

Thus says the LORD: See 2.2. Here translators may say “This is what the LORD, the God of Israel, says to you,” or better, “Listen to what the LORD, the God of Israel, says.” For God of Israel, see 7.3.

Cursed … covenant: See Deut 27.15-26, especially verse 26. Cursed be the man is in reality a passive construction, which may be stated in the active: “I, the LORD, the God of Israel, will place my curse upon everyone….” But since the Hebrew text is probably best understood as a present tense, Good News Translation “I … have placed a curse” is better. Note that the man should be understood to include both sexes: “Anyone who does not keep the terms of the covenant, I have placed a curse on that person.”

Most cultures are familiar with cursing. In normal usage, Cursed would have the idea of calling upon a god or spirit to do evil to someone. In this case, since it is the LORD who is cursing, translators can say something like “I cause evil to happen to anyone who does not keep the terms of our covenant.”

The words of this covenant: See Deut 29.1, 9 and verse 2 above. Revised English Bible, Good News Translation, and New American Bible translate “the terms of this covenant,” which is an accurate meaning in the context. To not heed the covenant means to not obey its conditions or terms.

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 .