Vayeilech - Shishi
That’d Be a Good Song to Have on Your iPod!
God said He would bring the Jews into the land, where they would live comfortably. Nevertheless, they'll abandon Him in favor of unliving idols. When they are afflicted as punishment, the song will testify on their behalf. Trust Him; God knows what the people are like.
So, Moshe wrote down the song and taught it to the people. God told Yehoshua to be strong, since He would be with Him. Moshe finished writing down the Torah.