Answer
There are at least three songs that Moses wrote. One was sung after the crossing of the Red Sea (Exodus 15), one is recorded in Psalm 90, and the other was written in the last days of Moses’ life, in Deuteronomy 32.
As his time on earth drew to a close, Moses tied up several loose ends in his ministry, following God’s instructions in setting everything in order. God told Moses to write a song, commonly called “The Song of Moses,” and teach it to the people (Deuteronomy 31:19, 30). The Lord then commissioned Joshua, Moses’ replacement (verse 23). Finally, Moses wrote down the entire Law as he had received it from God (verse 24) and gave it to the Levites to keep with the ark of the covenant (verse 25).
God required the Israelites to learn the Song of Moses in anticipation of their future apostasy in the Promised Land. God knew that, despite His blessings, Israel would turn their backs on Him and follow other gods, bringing divine judgment. When that happened, the song they had learned generations previous would “be a witness . . . against them. . . . When many disasters and calamities come on them, this song will testify against them” (Deuteronomy 31:19, 21). The Song of Moses had both a prophetic purpose (it predicted the nation’s falling away) and a didactic purpose (it taught the faithfulness of God and the consequences of sin).
The song that Moses recited to the people takes up the better part of chapter 32. Deuteronomy 32:44 says that Joshua aided Moses in the recitation of this inspired song. The same day that Israel learned the Song of Moses, God directed Moses to climb Mt. Nebo, where Moses would be laid to rest (verses 48–50).
The song begins with a universal call to listen, followed by praise of the just, faithful, and upright God (Deuteronomy 32:1–4). In contrast to God’s faithfulness is Israel’s unfaithfulness (verses 5–6). The song proceeds to recite the history of Israel from their time of bondage in Egypt, through their wilderness wanderings, to their established place in the Promised Land (verses 7–14). The Song of Moses then becomes prophetic: Israel’s future ingratitude and idolatry are predicted, as are the judgments of God for their sin (verses 15–31). Then God promises to avenge Israel against their (and His) enemies, showing compassion on His people (verses 32–42). The song ends on a joyful note, as God’s punishment is past, righteousness is restored, and the land of Israel cleansed (verse 43).
A major theme of the Song of Moses is God’s faithfulness. He is called “the Rock” four times in the song (Deuteronomy 32:15, 18, 30–31). Even as God’s people are chasing whims and trusting feeble gods, God remains their steadfast, unchanging Source of Salvation.
The last words of the Song of Moses are a promise that God will “make atonement for his land and people” (Deuteronomy 32:43). This is a significant promise, because the atonement for God’s people is none other than the sacrifice of God’s own Son, Jesus Christ (Colossians 1:20).