Abraham had the anointing, which is why he was called a "prophet" by God, because he believed and obeyed the Torah, which existed even before it was given in written form to Moses.
Now then, return the man’s wife, for he is a prophet, so that he will pray for you, and you shall live. But if you do not return her, know that you shall surely die, you and all who are yours.”
Genesis 20:7
When Abram was ninety-nine years old Yehovah appeared to Abram and said to him, “I am God Almighty; walk before me, and be perfect, that I may make my covenant between me and you, and may multiply you greatly.”
Genesis 17:1-2
I will multiply your offspring as the stars of heaven and will give to your offspring all these lands. And in your offspring all the nations of the earth shall be blessed, because Abraham obeyed my voice and kept my charge, my commandments, my statutes, and my Torah.
Genesis 26:4-5
Was not Abraham our father justified by works when he offered up his son Isaac on the altar? You see that belief was active along with his works, and belief was completed by his works
James 2:21-22
If he had not obeyed the commands of God no covenant would've been established with Abraham. His righteousness was imputed to him predicated both on belief and also obedience. Obedience to what? The oral Torah that existed then. And that is why we must not only believe, but also obey the Torah. You deceive yourselves thinking you do not need to obey. Foolish.