An excellent book on terms referring to the Latin Mass and background on the saint’s mentioned in the Latin Mass is “A Layman’s Guide to Latin Mass Terms: an A-Z Guide to Terms Concepts & Biographies of the Saints in the Mass” by Paul Byrne. If you plan to attend the Traditional Latin Mass, a good start is to scan a modern missal published from about 1950 to the most modern ones published around 1962, really the latest one approved by the Vatican. The next book you should read (or possibly concurrently with the missal to look up terms as you need to ) is this one, to understand what certain terms mean that are commonly used and the significance of certain holy days of obligation and “named” Sundays (e.g. The Ascension, Quadragesima Sunday, PENTECOST Sunday etc.).
I was confused some of the first times I saw Psalms referred to in some reading material and upon looking in my Bible had nothing to do with the subject matter I had just read. Eventually, I figured out it was not a clerical error, it happening so often, but was a numbering mismatch between versions of the Bible. This was caused by the fact, touched on in the title, that the Vulgate based on the Greek Septuagint, which the church selected for the accepted collection of Old Testament texts used for 1500 years, was different from the Bible as translated by Martin Luther and protestant reformers because the protestant reformers based their accepted collection of old testament texts based on the Hebrew Masoretic texts, to exclude texts (like the 2 Maccabees 12:46) which supported the concept of a purgatory since you could pray for people after they were dead, “that they be loosed from their sins.” Unless there is some intermediate plane of existence where God’s mercy allowed one who was not perfect (Matthew 5:48) to become perfect then people ether went to hell were there was no hope of salvation through prayer or otherwise (and how many people die, do you think, in a perfect state of grace?) or you went straight to heaven where there is no need to pray for someone, since he or she has arrived at the ultimate happiness, the goal set by God, union with Him, for all humans to strive for. Dogmas made up by Martin Luther and his ilk of “once saved always saved” would seem to me to lead to complicacy and ultimately laziness, both seemingly against scripture (Philippians 2:12, James 2:14-26, Matthew 24:13).
The following is an excerpt, the actual definition of one of the terms from the book “Lyman’s Guide to Latin Mass Terms” on the numbering of the Psalms:
PSALMS, NUMBERING OF
The numbering of the Psalms in the Vulgate, which is used in the Roman Missal, differs from that in modern Catholic, and Protestant, translations of holy Scripture. The difference arises from the manner in which certain psalms are divided or combined. The Vulgate adopts the numbering of the Greek Septuagint, whereas the more modern translations employ that of the Hebrew Maoretic text. Most modern vernacular Catholic, and all Protestant Bible translations employ that of the Hebrew Masoretic text. Most modern vernacular Catholic, and all Protestant Bible translations, employ the Masoretic numbering. The table below sets out the differences:
| ————————————|—————————–|
| Septuagint Vulgate | Masoretic Modern |
| Psalm Numbering | Psalm Numbering |
|————————————-|—————————–|
| 1-5 | 1-8 |
| 9 | 9-10 |
| 10-112 | 11-113 |
| 113 | 114, 115 |
| 114, 115 | 116 |
| 116-145 | 117-146 |
| 146, 147 | 147 |
| 148-150 | 148-150 |
|——————————————————————|
Traditional Thomistic Catholic 