John Calvin Commentary Deuteronomy 4:44

"And this is the law which Moses set before the children of Israel:" — Deuteronomy 4:44 (ASV)

And this is the Law. This last passage refers to the same thing: namely, that the Law was proclaimed anew when the people had now reached the threshold of the promised land. This was so that they might be more inclined to obedience, especially since the two and a half tribes had now, by the conquest of the Amorites, obtained a resting-place and a home. Indeed, their settlement is mentioned because the taste of the favor already received should stir up their zeal to proceed more cheerfully.

We will comment elsewhere on the country and names of places. It is sufficient here to remember that the memory of the Law was renewed after the sons of Reuben and Gad, and half the tribe of Manasseh, had obtained their inheritance outside the promised land, and when their assured possession was before the eyes of the rest.

But Moses shows that, although he might explain the Law in greater detail, still nothing had been added to the summary that was originally proclaimed. Instead, he indicates that whatever he had taught them during the forty years had no other purpose than that they might more faithfully and precisely keep the Law of God.