Commentary Purg XXI 14-15

The nature of the cenno (sign) made in response by Virgil has long puzzled the commentators.  We can say one thing with something like certainty: Virgil's gesture is not a spoken one, since he makes some sort of gesture and then begins to speak (verse 16).  Many early and some later commentators have liked the idea that in response Virgil said 'et cum spiritu tuo' (and with your spirit as well), a liturgical reply.  Yet it surely seems impossible that Dante would have first presented Virgil as speaking and then immediately afterwards as beginning to speak.  And so it is clearly preferable to understand that Virgil made some sort of physical gesture.  Perhaps the most sensible gloss remains that of Benvenuto (DDP Benvenuto.Purg.XXI.14-18): 'with similar reverence [Virgil] lowered his head to him.'  Previously Dante has clearly distinguished among parole, mani, and cenni (words, [actions of] hands, and signs) at [Purg I 50]; and he will distinguish between dir and cenno (speech and sign) at [Purg XXVII 139].  In fact, in the fifteen uses of the word cenno in the poem, this would be the only one in which it referred to speech, as Steiner (DDP Steiner.Purg.XXI.15) points out, adding that Virgil, as a pagan inhabitant of Limbo, is never permitted either to pronounce sacred phrases or to perform actions pertaining to Christian ritual (e.g., genuflexion).  The word <I>cenno</I> appears in the poem as follows: [Inf III 117], [Inf IV 98], [Inf VIII 5], [Inf XVI 116], [Inf XXI 138], [Inf XXII 8], [Purg I 50], [Purg VI 141], [Purg XII 129], [Purg XIX 86], here, [Purg XXII 27], [Purg XXVII 139]; [Par XV 71], [Par XXII 101].

      For the ingenious but perhaps not eventually acceptable notion that Virgil's cenno 'may very well be an embrace, a gesture analogous to the liturgical Kiss of Peace' see Heilbronn (Heil.1977.1), pp. 58-65.  Had Virgil been a Christian, Dante might very well have chosen to make Heilbronn right.  However, see Albrecht (Albr.2002.1), who argues that Virgil's gesture is the sign of the cross, offered without the accompanying response to the hopeful wish 'Dominus det nobis suam pacem' (May God grant us His peace) found in breviaries and in the liturgy of the hours: 'Et vitam eternam' (And eternal life); in Albrecht's view it is what Virgil did not say that is focal to the scene.  (For clear examples of facial gestures as cenni in this very canto, see [Purg XXI 104], Virgil's look that calls for silence, and [Purg XXI 109], Dante's smile that is a hint.)