Commentary Par IX 137-142

The two references are, first, to the Annunciation (when Gabriel 'opened his wings' to Mary in Nazareth), second, to all those martyred in Rome for their belief in Christ, starting with Peter (buried on the Vatican hill) and filling many a catacomb.  Thus the two exemplary groups bracket the birth and resurrection of Jesus, the one preparing the way for Him, the second following his path into a glorious death (and eventual resurrection).

Scartazzini (DDP Scartazzini.Par.IX.127-142) suggests that Dante's muffled prophecy is set in the context of crusading (see [Par IX 125-126]), without going on to suggest that it calls for a new crusade.  However, that does seem a real possibility.  At any rate, most commentators have given up on finding a precise formulation for understanding Folco's prophecy.  The 'usual suspects' have been, more or less in this order of popularity, the death of Boniface VIII, the removal of the papacy to Avignon, the coming of a great leader (e.g., on the model of the veltro and/or the DXV).  It would not seem like Dante to have a negative prophecy at this point (furthermore, the death of Boniface did not lead to a rejuvenation of the Church, nor did the 'Avignonian captivity'); nor would it seem like him to repeat a prophecy that he would then repeat still again in [Par XXVII 145] (the fortuna [storm at sea]) and which is primarily imperial, not ecclesiastical, as this one is.  And so it seems reasonable to suggest that Scartazzini may have been on the right track.  Fallani (DDP Fallani.Par.IX.139-142) comes close to saying so (without referring to Scartazzini).  And see Angelo Penna, 'Raab' (ED.1973.4, p. 817a), who says, in passing, that vv. 112-142 reflect crusading.  Mark Balfour (Balf.1995.1), pp. 140-41, sees the desire for renewed crusading in the Holy Land as permeating the conclusion of the canto, but follows exegetical tradition in seeing its very last lines as referring to the veltro or DXV.  The Church (and the entire context of this passage, vv. 133-142, which we hear in the voice of a [crusading] churchman, is ecclesiastical) will reorder itself only when it returns to its original purpose; for Dante, no matter how this may trouble modern readers (including Schildgen [Schi.1998.1]), that meant recapturing Jerusalem.