"Psalm 151 is the name given to a short psalm that is found in most copies of the Septuagint but not in the Masoretic Text of the Hebrew Bible. The title given to this psalm in the Septuagint indicates that it is supernumerary, and no number is affixed to it: "This Psalm is ascribed to David and is outside the number. When he slew Goliath in single combat". It is also included in some manuscripts of the Peshitta.
The Eastern Orthodox Church accepts Psalm 151 as canonical. Roman Catholics, Protestants, and most Jews consider it apocryphal. However, it is found in an appendix in some Catholic Bibles, such as certain editions of the Latin Vulgate, as well as in some ecumenical translations, such as the New Revised Standard Version."
Books can be attributed to "Anonymous" for several reasons:
* They are officially published under that name * They are traditional stories not attributed to a specific author * They are religious texts not generally attributed to a specific author
Books whose authorship is merely uncertain should be attributed to Unknown.
This is a poem about David killing Goliath. It's in the first person, but it has a very different style from David's other psalms. Catholics and Protestants don't have it in their Bibles, but the Orthodox church does. Found this on the internet: "There are a couple reasons why we do not include Psalm 151 in most Bibles. One is that the psalm was not part of the traditional or Masoretic Hebrew text. Traditional Judaism considers Psalm 151 to be part of the Apocrypha. Another is that, even though Psalm 151 appears in the Septuagint, the translators of that version marked it as “not of the number”; that is, they did not consider Psalm 151 to be an official part of the biblical canon." https://www.gotquestions.org/Psalm-15...