Starting right of the bat with this reading is pretty interesting, talking about different modes of prophecy:
But when you hear the utterances of the prophets spoken as it were personally, you must not suppose that they are spoken by the inspired themselves, but by the Divine Word who moves them. For sometimes He declares things that are to come to pass, in the manner of one who foretells the future; sometimes He speaks as from the person of God the Lord and Father of all; sometimes as from the person of Christ; sometimes as from the person of the people answering the Lord or His Father, just as you can see even in your own writers, one man being the writer of the whole, but introducing the persons who converse.
Then he goes on to give examples from Scripture where prophecy came as spoken by the Father, by the Son, and by the Spirit. That's pretty cool, and I wish someone had explained that to me in this manner when I was first introduced to prophetic writing. A little later, he also treats the question that always tripped me up, an always trips up my students whenever I teach from the prophetic writings: why are descriptions of future events written in the past tense?
CHAPTER XLII -- PROPHECY USING THE PAST TENSE.
But when the Spirit of prophecy speaks of things that are about to come to pass as if they had already taken place,--as may be observed even in the passages already cited by me,--that this circumstance may afford no excuse to readers [for misinterpreting them], we will make even this also quite plain. The things which He absolutely knows will take place, He predicts as if already they had taken place. And that the utterances must be thus received, you will perceive, if you give your attention to them. The words cited above, David uttered 1500 years before Christ became a man and was crucified; and no one of those who lived before Him, nor yet of His contemporaries, afforded joy to the Gentiles by being crucified. But our Jesus Christ, being crucified and dead, rose again, and having ascended to heaven, reigned; and by those things which were published in His name among all nations by the apostles, there is joy afforded to those who expect the immortality promised by Him.