So it was, when Moses had completed writing the words of this law in a book, when they were finished,
Deuteronomy 31:24
Surrounding context
31:23 Then He inaugurated Joshua the son of Nun, and said, "Be strong and of good courage; for you shall bring the children of Israel into the land of which I swore to them, and I will be with you."
31:24 So it was, when Moses had completed writing the words of this law in a book, when they were finished,
31:25 that Moses commanded the Levites, who bore the ark of the covenant of the LORD, saying: