Commentary Purg XXV 121

The hymn sung by the penitents of Lust has caused some confusion in the modern age because the hymn Summae Deus clementiae ('God of supreme clemency') does not seem appropriate to the recriminations of the lustful, while the hymn Summae Parens clementiae does.  However, the early commentators knew this hymn by the same first line as we today know the former.  Its text, in a form that is probably close to or identical with that known by Dante, is found in the commentary of Jacopo della Lana (DDP Lana.Purg.XXV.121-124).  The third stanza hopes for God's annealing fire to combat the passion of lust.