Deut 31:19

31:19 write this song. Knowing the people’s inclination to be unfaithful (v. 21), and realizing the power of song in worship and in memory, the Lord commands Moses to write a song that would serve as a testimony in future days. Other examples of Moses’ poetry include Ex. 15:1–18; 32:18; Num. 10:35, 36; and Ps. 90.