The clearest example of this is in Deuteronomy 34, which chronicles the death of Moses. Even evangelical readers recognize that Moses probably did not write about his own death before it happened, and so the question is when was this account rendered? Sailhamer proposes that it is at a time when prophesy in Israel had ceased (though we need not follow him in this conclusion to accept his general point), for in 34:10 there is this statement: "But since then there has not arisen in Israel a prophet like Moses, whom the LORD knew face to face" (NKJV). Sailhamer argues that this is later commentary upon the prophecy of Deut. 18:18, which says: "I will raise up for them a Prophet like you from among their brethren, and will put My words in His mouth, and HE shall speak to them all that I command Him." (NKJV). The later prophet is indicating that this Messianic promise has not yet been fulfilled. Indeed, in Acts 3:22-23 Peter preaches that Jesus is the fulfillment of Deut. 18:18, confirming its Messianic character.
The upshot of Sailhamer's proposal is that reading the Old Testament is not fundamentally different from reading the New Testament. What we have is later writers looking back upon older Scriptures and using them to evaluate the Messianic promises in light of the current situation. Thus, Hannah in her prayer to God in receiving Samuel in 1 Sam. 2:1-10 can look toward the anointed king promised in Numbers 24:7 (see Sailhamer, p. 16). Thus the entire canon of Scripture is a continual unfolding of promise, expectation, reflection, and fulfillment, wherein the process is one of continually going back to the Scriptures in order to evaluate the present redemptive and revelatory moment in light of what God has said. With a closed canon, of course, this unfolding is no longer revelatory in the sense of God's Word speaking anew, but it is revelatory in the sense of always understanding our present circumstances in light of the promises, expectations, reflections, and fulfillments of God's redemptive history as set forth in Scripture.