There will be no need for external teaching because people will simply know to follow the laws.
Many people already know the 10 Commandments from their heart; as when we break them, we feel the fact we're doing something wrong.
The 10 Commandments are the Laws that the Lord of Creation gave to Moses; the rest was his father-in-law telling him to make a law book to save time.
The 10 Commandments I saw in my Near Death Experience are Jacobs Ladder; where they are dimensional quantum physics.
As a return of the Messiah I've rewritten all 13 including the levels of Heaven, as
an advanced metaphysical guide for everyone.
This is a start to explaining them though, as it is possible to teach them as levels of ascension; once they're understood more clearly, then there doesn't need to be a teacher.
"No longer will they need to teach one another and say to one another, “Heed the LORD”; for all of them, from the least of them to the greatest, shall heed Me—declares the LORD."
This isn't saying what you think, that everyone will know the Source of reality (God - אל); it is saying they will know the Lord of Creation Avatar (יהוה אלה):
Where the Song of Moses (Exodus 15:2) said the Lord will become our Salvation (Yeshua - H3444); then the Song of the Lamb (Revelation 15:3) is that the Lord becomes the Head of the Flock (צאן - Zan/Tson).
Where we can show the symbolism that the New Name of the Messiah in Revelation 3:12, is a correlation of Sandalphon (Pillar in the Temple of God), Zion (the name of the New Jerusalem), Sananda (the New Name of Christ), and
the name of the Creator in many cultures was Zan.
To comprehend the chain of events in Isaiah 52:10 the 'Spirit of Salvation' was placed into the flesh of David (Yeshua Elohim); then in Isaiah 52:7 the Lord returns as 'Your Divine Being Zion' - Where Zion becomes the name of the Messiah (Psalms 146:10, Psalms 147:12, etc).
Just to be very clear as well, in Deuteronomy 32:15-22 it is saying because the Rabbinic Rebels have rejected their former religion (Deuteronomy 32:7-9), and created a form of Henotheism; where they've rejected Yeshua/Yehoshua (the Lord of Salvation) as their Divine Being (אלה - H433), and replaced it with an imaginary idea about Hashem - then the Source (אל) plans on annihilating everyone, unless I could get everyone to question their scriptures properly on here.
Personally would prefer 'the scriptures to become like a fire' under the Messiah (Jeremiah 23:29), and God doesn't have to destroy everyone for being ignorant of language, contexts, & theology.
In my opinion.