Commentary Purg XIV 85

The phrasing (sowing and reaping) is obviously biblical, as Lombardi (DDP Lombardi.Purg.XIV.85) was perhaps the first to note, citing St. Paul (Galatians 6:8): 'Quae enim seminaverit homo, haec et metet' (For what a man sows, that shall he reap).  Tommaseo (DDP Tommaseo.Purg.XIV.85-87) cites another five biblical passages that also rely on this metaphor, but the passage in Paul is favored by the commentators once it enters the tradition.  Here Guido, in purgation, harvests the straw of expiation for his sins on earth; his wheat awaits him in paradise.