Nothing can be added or removed from what God commands (Deut. 4:2; 12:32), but did you notice that Deuteronomy 18:15 extends the law of Moses to everything that God's prophet says?
The Lord your God will raise up for you a prophet like me from among you, from your fellow Israelites. You must listen to him. (Deut. 18:15 NIV)
I guess this could mean everything that God's prophets spoke in the rest of the Old Testament, but especially what Jesus said. So when the rich young ruler wanted to keep all of the commandments, this might be the one thing that he lacked: he needed to do whatever Jesus commanded. (Though maybe "love your neighbour as yourself" may have been his problem too, but Scripture does not say that explicitly)
Jesus looked at him and loved him. “One thing you lack,” he said. “Go, sell everything you have and give to the poor, and you will have treasure in heaven. Then come, follow me.” (Mark 10:21 NIV)
“
I will raise them up a Prophet from among their brethren, like unto thee, and will
put my words in his mouth; and he shall speak unto them all that I shall command him. And it shall come to pass, that whosoever will not hearken unto my words which he shall speak in my name, I will require it of him.”
Deuteronomy 18:18-19 KJV
….then he came and spoke
“
He that rejecteth me, and receiveth not my words, hath one that judgeth him:
the word that I have spoken, the same shall judge him in the last day.
For I have not spoken of myself; but
the Father which sent me, he gave me a commandment, what I should say, and what I should speak. And I know that his commandment is life everlasting: whatsoever I speak therefore, even as the Father said unto me, so I speak.”
John 12:48-50 KJV
And then Peter filled with the spirit afterwards teaches
“
Repent ye therefore, and
be converted, that your sins may be blotted out, when the times of refreshing shall come from the presence of the Lord;
and he shall send
Jesus Christ, which before was preached unto you: whom the
heaven must receive until the times of restitution of all things, which God hath spoken by the mouth of all his holy prophets since the world began.
For
Moses truly said unto the fathers, A prophet shall
the Lord your God raise up unto you of your brethren, like unto me;
him shall ye hear in all things whatsoever he shall say unto you. And it shall come to pass, that every soul, which will not hear that prophet, shall be destroyed from among the people.
Yea, and
all the prophets from Samuel and those that follow after, as many as have spoken, have likewise foretold of these days.
Ye are the children of the prophets, and of the covenant which God made with our fathers,
saying unto Abraham, And
in thy seed shall all the kindreds of the earth be blessed.
Unto
you first God, having raised up his Son Jesus, sent him to bless you, in turning away every one of you from his iniquities.”
Acts 3:19-26 KJV
so this is
specifically about Jesus and what he said in the gospel
moses was foretelling tbat “
when he comes everyone one needs to heed his words those words will be Gods requirement “
“I will raise them up a Prophet from among their brethren, like unto thee,
and will
put my words in his mouth; and he shall speak unto them all that I shall command him. And it shall come to pass, that whosoever will not hearken unto my words which he shall speak in my name, I will require it of him.”
In the Bible in the law and prophets of the ot there’s a message of Christ , always in some way promises of Jesus to come. In this case the words Jesus would speak the new covenant
For instance everyone knows isaiah 53 but also after that
“Ho,
every one that thirsteth, come ye to the waters, and he that hath no money; come ye, buy, and eat; yea, come, buy wine and milk
without money and without price. Wherefore do ye spend money for that which is not bread? and your labour for that which satisfieth not? hearken diligently unto me, and eat ye that which is good, and let your soul delight itself in fatness.
Incline your ear, and come unto me: hear, and your soul shall live; and I will make an everlasting covenant with you, even the sure mercies of David. Behold, I have given him for a witness to the people, a leader and commander to the people.”
Isaiah 55:1-4 KJV
jesus is the only ne who made the everlasting covenant the one Moses foretold would rise up with the words of God the people in Deuteronomy 18 had begged not to hear anymore from the Mount . The same promises Moses wrote of given to Abraham Isaac and Jacob of a seed that would be a blessing. And savior to all peoples
the ot is about Jesus when it comes to Gods word it’s the things Jesus taught Moses taught contrary things in the law
we need to hear and learn God from Jesus like Moses said and not from an ancient law made for people without the holy ghost
wirhin the law and prophets is a witness of Jesus all the way through even about the words and law that would come from him if the people listened to him
“
Hearken unto me, my people; and
give ear unto me, O my nation: for a law shall proceed from me, and I will make my judgment to rest for a light of the people.
My righteousness is near; my salvation is gone forth, and mine arms shall judge the people; the isles shall wait upon me, and
on mine arm shall they trust.”
Isaiah 51:4-5 KJV
It was always Jesus who would be the lawgiver Moses law was meant to reach to Jesus