"For the whole body of those rightly handling the word of truth, the manifold wisdom of the word of God, we especially beseech [thee. Lord have mercy]."

"Pro universis recte tractantibus verbum veritatis, multiformem Verbi Dei sapientiam peculiariter obsecramus.  [Kyrie eleison.]"

     Third petition of the late 5th-century "Deprecatio Gelasii" (PL 101, cols. 560-562; Capelle, below, p. 136), "le fleuron des litanies anciennes".  The "Deprecatio Gelasii" was a Western adaptation of an Eastern litany more ancient still.  For a critical edition, see B. Capelle, "Le Kyrie de la messe et le pape Gélase," Révue Bénédictine 46 (1934): 136-138 (126–144), which indicates that this petition is present in 9th-century Paris 1153 ("le seul connu"), f. 48v-49r, but absent from the abridged version at Angelica B. 3.18, f. 213r.  Cf. 2 Tim 2:15 ("recte tractantem verbum veritatis") and Eph 3:10 ("multiformis sapientia Dei").
     I was put onto this by Paul de Clerck ("Improvisation et livres liturgiques:  leçons d'une histoire," Communautés et liturgies 60 (1978):  117 (109-126)), who overlooks (at least here) the allusion to Eph 3:10, but notes that there was a falling away or impoverishment after this point (petition no. 3 of the Franco-Gallican litany or prayer of the faithful reads merely

"For our pastor and all his clergy, we implore you"

(Paul de Clerck, La «prière universelle» dans les liturgies latines anciennes:  témoinages patristiques et textes liturgiques, Liturgiewissenschaftliche Quellen und Forschungen 62 (Münster Westfalen:  Aschendorff, 1977), 187-205), a falling away that necessitated the rise of liturgical books (the libelli, then sacramentaries, that were the outcome of "the great 6th- [and post 6th-]century movement of compilation" (118)), i.e. a recognition that liturgical improvisation needed guidance (rich models; "books for the [support of] liturgy" rather than rigidly prescriptive "liturgical books" (118)); that early improvisation (characteristic of "the whole of Christian antiquity" up through the end of the 4th century (112)) had been "informed, not informal" (111); "directed" (119), rather than spontaneous; guided "by [1] general structures", [2] outlines (even, sometimes, written outlines) of prayers, and [3] the prodigious retentive capacities of an oral culture (113).  For these reasons it did not result in "The monotony of a malnourished liberty [(La monotonie d'une liberté mal nourrie)]" (Louis Bouyer, L'improvisation dans l'Eglise ancienne, 15, as quoted on p. 120) or any marked declination from orthodoxy (115 ff.).