For or against Psalm 151?

Here is wiki about it:

Psalm 151 is a short psalm found in most copies of the Septuagint[1] 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".[2] It is also included in some manuscripts of the Peshitta. The psalm concerns the story of David and Goliath.

The Eastern Orthodox Church as well as the Coptic Orthodox Church, Armenian Apostolic Church and the Armenian Catholic Church[citation needed] accept 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. Psalm 151 is cited once in the Extraordinary Form of the Roman Breviary, as a responsory of the series from the books of Kings, the second in the Roman Breviary, together with 1 Kings 17:37 in a slightly different text from the Vulgate.[3]

The phrase "Extraordinary Form of the Roman Breviary" is synonym with Traditional Roman Breviary. It is in use among those accepting the New Breviary as the Ordinary Form. So, Psalm 151 is cited in Traditional Catholic liturgy.

Now, the text given on wiki for it is fairly different from this text, which is obviously not an identic one:

Tentative translation:

[1] You have cursed ('lt), Anakite (`nq), against (b) the servant of God (`bd 'lhm);
[2] the servant of God (`bd 'lhm) has judged you (sha-pa-t.a-ka), with (b) judgements of Yahu (mi-shi-pi-t.i ya-hu);
[3] Goliath (glyt), you are dead (mtt); David (dwd) is master (b`l) for ever (lns.h.m);
[4] I arise ('qm) and we raise up (nrm) the foundation (ysd) of my kingdom (mlky);
[5] I raise up ('rm) the people (`m) of my servant (`bdy) for his virtuous acts (`l s.dqtw).

From : THE DAVID AND GOLIATH OSTRACON
AND THE ESHBAAL JAR FROM KHIRBET QEIYAFA (SHA`ARAYIM? )
Brian E. Colless
https://sites.google.com/site/collesseum/qeiyafa-ostracon-2

Cited in : Patterns of Evidence : David vs. Goliath: Is There Evidence?
by Steve Law | Oct 26, 2018 | Evidence |
https://patternsofevidence.com/blog/2018/10/26/david-battles-goliath/

So, it is not utmost direct evidence for Psalm 151, since it is a different text. But is it in any way shape or fashion evidence against it?

I would say, no, since arguably there could be other texts than Psalm 151, if by King David, and obviously mentions in I & II Samuel, I Chronicles and Ecclesiasticus 47:5, which are canonic, are ot exhaustive either.

The text on the ostracon could have been a comment by Samuel, even a prayer said before the event, or a comment by someone knowing to write, but not inspired.

The words are put in the mouth of God alternating with a prophet, and those of psalm 151 are by contrast purely the words of David, the future king.

So, the ostracon is not evidence against it either.

My own hunch is, it could be by David, and the incident is after he was anointed, so, already by an anointed King David, but he could have composed it while impure after the slaying of Goliath, and therefore not counted it among the psalms proper.

Hans Georg Lundahl
Cergy St. Christophe
Vigil of Sts Simon and Jude
27.X.2018