For the longest time, Indian scriptures were recited from generation to generation
Overtime, certain minor errors may creep in. These errors can only be detected by an enlightened person
Why ? Since he has experienced it and knows the method of experience also
As such, when you can boldly say no books are needed, then you are on the right track. Then when you read scriptures, you may, on occasion, see the minor error in translation or recitation
Or the person who wrote the scripture will appear in person, tell you exactly what he said and you smile and bow to the great beings
This is Yoga
Bhavin