I think you are correct that many private interpretations have crept into the explanations of Gods Word. Of which God says "no prophesy of the scripture is of any private interpretation."

The Greek word for private is the word idios. Translates to "one's own" as in one's own interpretation. Also, the word idios is the basis for a word we throw sroumd here alot misusing it.

Anyway, the Bible has to interpret itself. In the word, in the verse in the chapter, in the Bible. Thknk first usages... same as a human author.