Certainly the ‘Iudica me’ is a holy and proper prayer before ascending to the altar, and it warrants no criticism on my part. Everyone should before going to assist at Mass (Catholics do not merely attend, but in a real and spiritual sense, we assist at the Holy Mass), offer prayers to God to prepare themselves for participation in the sublime and most holy mysteries of the Sacrifice of the Mass. What is pointed out above is merely that the ‘Iudica me’ is not of itself essential to the Sacrifice of the Mass.The use of the Psalm varies much more greatly than proponents of the Classical Roman Rite will generally lead others to believe. At the same time, one can certainly appreciate the expression of love for this Psalm from those who have a special attachment to the older liturgy. It cannot be considered a theological aberration to omit or to include the Forty-second Psalm. Its omission cannot justify the claim that the 1970 Missale Romanum has been protestantized for then we must hold the same to be objectively true for those rites wherein it is not used.
These Introductory prayers (The Antiphon, Psalm Forty-two, the Confiteor and two prayers at the end) were the last developed of the various portions of the preparatory part of the Mass. They are first mentioned from the eleventh century. Preparatory prayers were indeed recited at a much earlier period; but they were not so rigorously prescribed, and did not belong strictly to the Mass liturgy, as they were generally said in the sacristy or on the way to the altar, while the choir sang the Introit Psalm. All known liturgies begin with a kind of confession of guilt. In former times the formulas differed greatly: the classic Roman form for the Confiteor appears to have been in general use since the thirteenth century.3 The very fact that some of the preparatory prayers are omitted and that various forms of the others are used; verifies my assessment that they are not per se required in the liturgy for validity but their long historical development and traditional uses also establishes for them a place of honor and they properly belong to the older Roman Missal.
1 Rev. Dr. Nicholas Gihr, The Holy Sacrifice of the Mass: Dogmatically, Litugically and Ascetically Explained, 1877 1st edition, 1897 6th edition, translated from German ©1902, printed 1924, Pg. 353 Cf. footnote 1.
2 Ibid, Pg. 356 Cf. footnote 2, cites Romsee, T.I., Opera liturgica. Mechlinae 1838.
3 Ibid, Pg. 346 Cf. footnote 1. “The assertion that Pope Celestine I. (422-432) gave the Psalm Iudica its present position, is entirely untenable. Cf. Bona, Ioann., Cardinalis, Ord. Cist., Rerum liturgicarum libri duo. Studio et labore Rob. Sala. Augustae Taurinorum 1763.”