Commentary Par XXVI 67-69

See Getto (Gett.1968.1), pp. 942-43, discussing Dante's formula for concluding the apostles' examinations of him on the three theological virtues.  These occur at [Par XXIV 112-114], [Par XXV 97-99], and in these verses.  Getto finds the three texts sharing the following earmarks: each passage (1) is contained in no more or no less than a single terzina; (2) contains reference to Dante's completion of his utterance; (3) cites the opening words of the celebrative song raised at its conclusion; (4) includes some description of the quality of that song; (5) refers to those who sang it.

Once again we find a Latin hymn (the Sanctus), which had become a part of the liturgy, performed in Italian ('Holy, holy, holy').  See C.Par.XXIV.113-114.  The original Sanctus is found in both Isaiah 6:3 and Revelation 4:8 (where it follows the description of the 'four living creatures' [see C.Par.XXVI.53]).