Actually, I did very much address your grammar points, but not in a way that you seem satisfied.
You are removing two words out of context of the whole to hold to your presentation.
Making a prophecy uniquely, distinctly, personal property, is not prevented from the READER. The reader has the freedom to do with the Scriptures as they choose.
What is prevented is the WRITER making the prophecy uniquely, distinctly, personal property of their own. That is they have no title, warranty deed, or claim that they exercised any control over the Scriptural prophecy.
Peter is emphasizing that "we have the prophetic word
made more sure" not that the reader cannot make decisions concerning how a prophecy is applied or even if the prophecy is applied.
Peter is contending through out this passage and following chapter, that which is Scripture prophecy in comparison to that which is false and unstable prophecy.
Peter has shown that the Scripture prophecy comes directly and verbally from God.
As far as the word translated "Interpretation" as I already discussed with you, this is not a word used in the NT, but unique to 2 Peter. It because it is coupled with unique means that the prophecy is God's solution, God's determination to accomplish. The prophecy comes from God, not from the false conjuring of the world(ly).
John, I would include this from the "Expositor's Bible Commentary." It is a bit lengthy, but perhaps better than I am writing.
"Knowing this first, that no prophecy of Scripture is of private interpretation." The Greek words need to be taken account of before we can gather the true meaning of this clause. That which is translated "is" is much more frequently rendered "comes to pass," and bears the sense of "arises," "has its origin."
"Interpretation" is the translation of a word which occurs here only in the-New Testament, and implies the "loosing" of what is complicated, the "clearing" of what is obscure. The lesson which the Apostle would give relates to the right appreciation of the Old Testament Scriptures, which contain the prophecy which he has called above "the lamp in a dark place." He intends to say something which may incline men to follow its guidance. The prophetic writings furnish us with illustrations how the problems which arose in the lives of the men of old time, both about events around them and also about the dispensations of Divine providence, found their solution. Thus they furnish rules and principles for time to come; and that men may be induced to confide in their guidance is the object of St. Peter’s words. He bids the converts know that these unravellings and clearings of the ways of God are not men’s private interpretation of what they beheld. This was not the manner in which they came to be known.
They are not evolved out of human consciousness, pondering on the facts of life and the ways of God, nor are they the individual exposition of those whom God employed as His prophets. They are messages and lessons which came from one and the same impelling power, from one and the same illuminating influence, even from God Himself, and so are uniform in spirit and teaching from first to last; and He from whom and through whom they are given can say by the mouth of the last of the prophetic body, "I am Jehovah; I change not." {
Malachi 3:6}
Although the Apostle uses in this Epistle the word "Scriptures" {
2 Peter 3:16} for the writings of New Testament teachers, it is not likely that he in mind included them among the prophetic Scriptures of which he here speaks. We, knowing the flood of light which the Gospels and Epistles pour upon the Old Testament, can now apply his words to them, fully perceiving that they are a true continuation of the Divine enlightenment, another spring from the same heavenly fountain.
Those who would explain "interpretation" as the judgment which men now exercise in the study and application of the words of Scripture forget the force of the verb (γινεται) "comes to pass," and that the Apostle is exalting the source and origin of the words of prophecy, that he may the more enforce his lesson, "Ye do well to take heed to them."
