Yeshua told the devil, “We are to live by every word that proceeds from the mouth of God.” The words of God are not limited to the “New Testament,” as a number of Christians assume. Yeshua said, “If you love me keep my commandments.”
We believe with all our hearts that Yeshua and the Father are “one.” We understand that the words of the Torah are Yeshua’s words, just like the Sermon on the Mount/Plain are Yeshua’s words.
Deuteronomy is not just repeating the prior books like a parrot but adding and elaborating on prior teachings. It shows us not just the words of God but the heart of God. When you love someone you want to know what is in their heart.