Devarim 31:21-23

Orthodox Jewish Bible

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.

²³ And he gave Yehoshua ben Nun a charge, and said, Chazak! And of a good courage; for thou shalt bring the Bnei Yisroel into Ha’Aretz which I swore unto them; and I will be with thee. [Isa 49:8]