Deuteronomy 31:19

31:19 Now write down for yourselves the following song and teach it to the Israelites. Put it into their very mouths so that this song may serve as my witness against the Israelites!

Deuteronomy 31:21

31:21 Then when many disasters and distresses overcome them this song will testify against them, for their descendants will not forget it. I know the intentions they have in mind today, even before I bring them to the land I have promised.”