Many evils and troubles have come upon them: see verse 17.

This song shall confront them as a witness: this is a court setting; the Israelites are being judged and the song is a hostile witness (see verse 18). In many languages it will be possible to retain the vivid imagery of a song standing “as evidence” (Good News Translation). But in some languages it will be difficult to talk about a song confronting someone as a witness. In such cases translators may follow Contemporary English Version: “I will remind them that they know the words of this song”; but even better may be “they will remember the words of this song and will realize that I am punishing them.”

(For it will live unforgotten in the mouths of their descendants): this means that the song will have been taught to the descendants of the generation that will occupy the land, and they will know why God is punishing his people.

I know the purposes which they are already forming: the noun translated purposes is often used of an instinct, mostly evil, which leads people to do evil things (see Gen 6.5; 8.21). This is expressed in New International Version as “I know what they are disposed to do”; New Jewish Publication Society’s Tanakh has “I know what plans they are devising even now,” and Revised English Bible “I know which way their thoughts incline.” Something like “I know what their [evil] impulses are” will be satisfactory in some languages.

Quoted with permission from Bratcher, Robert G. and Hatton, Howard A. A Handbook on Deuteronomy. (UBS Helps for Translators). New York: UBS, 2000. For this and other handbooks for translators see here .