Devarim 31:20-22

Orthodox Jewish Bible

²⁰ For when I shall have brought them into ha’adamah which I swore unto Avotav (their fathers), zavat cholov u’devash (that floweth with milk and honey); and they shall have eaten and filled themselves, and grown fat; then will they turn unto elohim acherim, and serve them, and provoke Me, and break My Brit.

²¹ And it shall come to pass, when ra’ot rabbot and tzarot are befallen them, that this shirah shall testify against them as an ed (witness); for it shall not be forgotten out of the mouths of their zera; for I know their yetzer (inclination) in which they go about, even now, before I have brought them into ha’aretz which I swore.

²² Moshe therefore wrote this shirah on that day, and taught it the Bnei Yisroel.