The importance of exclusion
After finding at least a date range for the book, it is important to understand the frame of reference for the target audience including the revealed Scriptures, the state of the world at the time, and the culture in that area. For example, a post exile Jew would have a very different view of the world when compared to a Jew in Solomon's kingdom. Not to mention the amount of Scripture that would be available (or at least in existence) for the former would far exceed the amount for the latter. And while we can study Ruth in light of Judges, we should not look for help with the time-locked message of Ruth in the Davidic Psalms.
We must start to exclude books of the Bible that were written after the date that has been established for our study passage. This in and of itself can be a daunting task as there are quite a few books that have a range of possible dates, however, if we apply a little common sense, we can safely exclude books that may have been written at the same time but would not have had been widely distributed at the time. We are truly blessed to have the completed Word of God!
The second thing that we may need to exclude is historical events that happened after the target passage/study. For example, reading a prophecy in Daniel from today's perspective is pretty straightforward; God called it! But to the original audience, it would have a whole other meaning, perspective, and purpose. Knowing history is very helpful in the other two perspectives, but it can be a hindrance in the time-locked if we're not careful.
A third exclusion candidate is modern theological concepts that may not have been revealed. For example, while the Old Testament testifies to the Messiah coming to die as the final sacrifice, that knowledge was shrouded in mystery. However, in Acts, the apostles used the Old Testament to preach Jesus Christ crucified, buried, and risen, and the Word had great effect on the hearers, even to salvation!
Another modern theological concept that might have to be ignored for Old Testament books is the great mystery revealed in Ephesians - that the Jews and Gentiles are both equal sharers in the body of Christ! While there are hints in the Old Testament of the reality of this concept, it is definitely not stated plainly or understood by any of the original hearers of the Old Testament. Jonah would be a prime example of this.
There are several other ideas expressed in the New Testament (permanent indwelling of the Holy Spirit, types of Christ, fulfillment of the Law in Jesus Christ, and more) that may need to be excluded from our thinking when addressing any Old Testament book from the time-locked perspective.