Today’s first reading is from the Book of Sirach. It is one of the books that the Catholic Church refers to as a deuterocanonical book, also called apocryphal books by Protestants. Catholics include these deuterocanonical books as part of the canon, whereas most Protestants do not, though some do still find value in them.
The deuterocanonical books are Tobit, Judith, 1 and 2 Maccabees, Wisdom, Sirach, and Baruch. There are also additions to the Book of Daniel and the Book of Esther.
So, where do these books come from? Well, they come from the Jews, though it is a common misconception that the Catholic Church added these books to the Bible. When a group of Jews in Alexandria Egypt decided to translate the Hebrew Bible into Greek (a translation referred to as the Septuagint), these additional books became a part of that collection. However, these books did not become a part of the collections used by Jews in other places like Palestine. Thus, Jewish believers in different areas had different books in their Bibles.
It just so happens, however, that the earliest Christian Church was made up of a considerable number of Greek speaking people. So, the Greek translation of the Hebrew Bible, which contained the deuterocanonical books, made its way into wide use among the early Christian church.
Not everyone was agreement about whether or not these books belonged in the Bible. For example, St. Jerome included them, but only as an appendix to the Old Testament. However, these books remained a part of the Christian canon of scripture up until the Protestant reformation.
At the time of the Reformation, the Protestant churches decided to go back to the canon of the Jewish scriptures and took out the deuterocanonical books. However, they maintained the Catholic ordering of the books, for when the Hebrew Bible had been translated into Greek the order had been changed.
What is the main point behind this? Essentially, religious communities make decisions about which books belong in a canon. Jews have a canon of scripture, Catholics have one, Eastern Orthodox Christians have one, and Protestants have one. But, in order for this to happen, the religious community/church must be invested with some authority. This is not a statement that some of the Christian traditions would agree with, but even some Protestants recognize that without the church having some sense of authority it is difficult to see how we would have ended up with a fairly uniform canon of scripture at all.