Commentary Par XXVI 5-6

These lines bring back to mind a similar tactic on the part of Virgil ([Inf XI 10-15]), where Dante's olfactory sense must be rested from the infernal stench before the downward journey into the pit may be continued; therefore, Virgil, in order to pass the time profitably, offers his 'lecture' on the order of the sins.  Here, in response to Dante's temporary blindness, John will use the time to give Dante his examination on Love, which begins with the next tercet.