Write this song and teach it to them

Moses has already written the book and put it beside the ark, which this volume studied in Week Six. Then God tells him to do one more thing, and it is a curious one.

Write a song. Teach it to them. Have them sing it.

And then the reason, in the same verse and the next: so that it may be a witness for Me against them. The same job the book had — but delivered as music.

The explanation follows immediately, and it is unsparing about human memory.

This song will testify against them, because it will not be forgotten by their descendants.

God says the song will survive when the book is neglected. Not because the song is more true, but because of how songs live in people.

That is a statement about media, made by God, in Scripture, about His own Word.

And the song He commanded is not comfortable. Deuteronomy 32 has Israel growing fat and kicking, forsaking the God who made them, sacrificing to demons. It calls them a warped and crooked generation. That is what they were told to memorize and sing.

Which is worth weighing against the usual assumption that music in worship is for encouragement. The first song God ever commanded a nation to learn was a prosecution brief, given so that when the judgment came they would already know the words.

The verse says why it works: I know what they are disposed to do, even before I bring them into the land I promised them on oath. The song was written in advance of the failure, by someone who knew the failure was coming.

And there is a warning in it for anyone who chooses what a congregation sings. If a song will outlast the sermon, the doctrine in the song had better be right — because what people sing is what they will still be able to recite when they have forgotten everything else, including on the day they most need it.

So this slot in the volume adds a form the earlier weeks did not have. Moses wrote a book to be deposited and read. He also wrote a song to be memorized and sung. Both were witnesses. Both were commanded. And the one God says will not be forgotten is the one with a tune.

Deuteronomy 31:22 records the compliance flatly: so Moses wrote down this song that day and taught it to the Israelites. Chapter 32 is the song itself, and 31:30 says he recited the words in the hearing of the whole assembly.

Ancient societies transmitted enormous quantities of material orally, and metrical or musical form is a preservation technology — rhythm and melody constrain the words and make corruption audible. The command in verse 19 is using a known mechanism deliberately.

The Song of Moses reappears in Revelation 15:3, where those victorious over the beast sing the song of Moses the servant of God and the song of the Lamb. Whatever that means in detail, the song commanded in Deuteronomy is still being sung at the end of the canon.

Note that the Psalter is Israel’s hymnbook and also Scripture, quoted more often in the New Testament than any other book. The overlap between what is sung and what is authoritative is built into the Bible’s own structure.

Note that God dictates the reason before the song is written: they will turn to other gods, break the covenant, and many troubles will come upon them. The song is composed as evidence for a trial that had not yet happened, by someone who knew it would.

Look it upH7892 שִׁירָה shirah, song · H3789 כָּתַב kathab, to write · H7760 שִׂים sim, to put, place · H5749 עוּד ud, to testify, bear witness

Then read Colossians 3:16 from Week Five again with this day in mind: let the word of Christ dwell in you richly, teaching and admonishing one another with psalms, hymns and spiritual songs. Paul puts teaching and singing in the same clause, and Deuteronomy 31 is why that is not decorative.

Where this touchesDeuteronomy 31:14–30; 32:1–47 · Colossians 3:16 (Week Five, Day Seven) · Ephesians 5:19 · Revelation 15:3 · Psalm 78:1–8. Jeremiah, Luke, John, Revelation, Peter, Moses, Paul, the prophets, the Proverbs collectors, Peter on Paul and the chronicler gave the earlier accounts.