I am sure that someone, somewhere has written on the implications of Galatians 3:8 for our understanding of inspiration. In fact I'm pretty sure that I've read someone, in some place, write on said implications, but my theological library is, at present, in boxes in my garage and I'm not going to do literal heavy lifting in order to write a blog post.
The Curmudgeon family was listening to a sermon one Sunday evening when I was struck by the first part of Galatians 3:8: "And the Scripture, foreseeing that God would justify the Gentiles by faith, preached the gospel beforehand to Abraham…." The subject of that sentence is "the Scripture," not "God;" Paul asserts that the Scripture preached. Moreover, the Scripture even foreknew the eternal plans of God: Scripture is the mind of God. For all intents and purposes, "Scripture" is another name for "God" in Galatians 3:8.I can't think of a clearer example of the Bible's understanding of itself as literally the divine voice itself. Galatians 3:8 is the necessary consequence of 2 Timothy 3:16, "All Scripture is breathed out by God…."