Deuteronomy 31:19

19Now therefore write athis song and bteach it to the people of Israel. Put it in their mouths, that this song may be ca witness for me against the people of Israel.

Deuteronomy 31:21

21And when many evils and troubles have come upon them, this song shall confront them as da witness (for it will live unforgotten in the mouths of their offspring). For eI know what they are inclined to do even today, before I have brought them into the land that I swore to give.”
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