It is difficult to accurately preach Jesus from the Old Testament. One danger is to over-spiritualize the OT with the result that you allegorize the passage.
In order to avoid both mistakes, I like to use Beale and Carson’s Commentary on the New Testament Use of the Old Testament (a tip I picked up from Keller, though I don’t remember where).
The cool thing about this commentary is that it works backward, too. By checking the Scripture index in the back, you can quickly find where they comment on your OT passage, and, therefore, see where it is either quoted or alluded to in the NT.
Once you see that your OT passage is referenced in the NT, you have the strongest and most accurate way to relate it to Jesus and the gospel.