Deuteronomy 31 is Moses’s pep talk to Israel before they enter the Promised Land. But it’s no mere game they’re preparing for; the nation is about to embark on a quest that will lead them into deadly battle. Yahweh commands them to destroy a group of tribes that have long engaged in behavior he finds reprehensible: idol worship, detestable religious sexual rites, child sacrifice, and rampant injustice.

“Be strong and courageous,” Moses encourages the people (v. 6). Significantly, they’ll be displaying whatever strength and courage they can muster without Moses’s leadership (v. 2). He’s handing the reins to Joshua (v. 3). In the presence of all Israel, Moses repeats the rallying cry to his successor: “Be strong and courageous” (v. 7). Yahweh himself will speak those words to Joshua soon after Moses dies (Joshua 1:6–7). But the quest doesn’t rest on Joshua’s shoulders. Moses told the people, “The Lord your God himself will cross over ahead of you” (Deuteronomy 31:3). Joshua is simply Yahweh’s chosen agent.

Choosing Wisely

If Yahweh were to lead them, the people would need to follow his instructions closely. So Moses reaffirmed the Law given to him by Yahweh at Mount Sinai and recorded it here in the book of Deuteronomy (chs. 5–28). Israel’s longtime leader has just emphasized a series of blessings and curses to the people (chs. 27–30). If they do well and heed Yahweh’s commands, they’ll experience his blessing. The flipside, however, horrifies us. If they reject Yahweh (and they will), they will face curses so dire that one day their descendants will cannibalize their own children (28:53–57). Moses wants to prevent such horrors from taking place, so he commands the people to read this law together as a nation. He directs them to do this every seven years and to include their children and the foreigners living among them (vv. 9–13).

Israel serves a God who referred to himself as “the Lord your God” eight times in the Ten Commandments alone (5:6–16). This is their God, in opposition to all the gods of the people they will soon displace. Keeping the Law identifies them with the God who gave the Law.

Having “finished writing in a book the words of this law from beginning to end” (v. 24), Moses gives the entire law “to the Levites who carried the ark of the covenant of the Lord” (v. 25). He instructs them to keep it in the ark of the covenant. We might think this is cause for celebration, a fitting culmination for a document that will guide and define them as a people. But Moses issues a somber warning: “There it will remain as a witness against you” (v. 26).

Why is the Law a witness against them? Because Yahweh knows what will happen. His people will do exactly what they have been warned against—forsake Yahweh and turn to idols.

A Symphony with Many Movements

Moses puts this warning into song, preserved for us in the next chapter of Deuteronomy, and then infuses it with a prophetic message. Although it declares Yahweh’s love for his people, this song is ill-suited for a love ballad. Rather, it seems to be a work with several disparate movements, more fitting for a metal band than a lovestruck crooner. The pleasant introduction (32:1–4) soon gives way to a jarring indictment. Calling Israel “a warped and crooked generation,” Moses asks, “Is this the way you repay the Lord, you foolish and unwise people?” (vv. 5–6). Shifting again, the song urges them to “remember the days of old” (v. 7).

Then, the music seems to soar as Moses reviews what Yahweh has done for them. But again, the mood darkens. Anticipating a time when the nation will forget Yahweh’s Law, Moses says, “They made him jealous with their foreign gods and angered him with their detestable idols” (v. 16). When this happens, Yahweh will “heap calamities on them” (v. 23).

But Yahweh remains true to his word. He can never forget them. And so the song lifts us again. “The Lord will vindicate his people and relent concerning his servants when he sees their strength is gone” (v. 36).

This militant musical piece, rife with warnings and consequences, nonetheless ends with a call to rejoice. And it is a call to all of us. “Rejoice, you nations, with his people, for he will avenge the blood of his servants; he will take vengeance on his enemies and make atonement for his land and people” (v. 43). Again, why?

Our attempts at justice inevitably fall short. Yahweh says, “It is mine to avenge; I will repay” (v. 35), a prospect that simultaneously terrifies and exhilarates. His righteous character is the only appropriate answer to our deep desire for justice in this world—complete justice that will unite the nations. This is more than reason to rejoice. This is reason to worship the God who gave the Law, and who gave us his Son to fulfill it.

—Tim Gustafson