The Treasury of Scripture Knowledge (TSK in SwordSearcher) is probably one of the most important Bible study aids ever published. Many Bibles have cross-references in their margins, but these are typically anemic. The TSK is like a Bible margin as wide as the Bible text column itself. I love this resource because it is all about interpreting Scripture with Scripture. It does contain some commentary text, but that is limited, as the focus is on showing how words and phrases from each verse are used elsewhere in the Bible.
It’s part of SwordSearcher (shameless plug), but if you want a printed version, be sure to get the old (not newly revised) version. You might be able to find it at a bookstore, and it’s available used on Amazon for a few bucks. My Revell printing of the original TSK has ISBN number 0-8007-0324-3.