Commentary Par XV 97-99

'The old line of walls dated from 1078 A.D. (Villani, iv. 8); it was now "old," because the wall of Dante's time was commenced in 1284....  The Badia [the church of S. Stefano in Badìa], the chimes of which are here referred to, stood just within the ancient walls; the Florentines took their time from these....  The factions and civil dissensions in Florence did not commence until 1177' (DDP Tozer.Par.XV.97-99).

In his commentary to these lines, Benvenuto (DDP Benvenuto.Par.XV.97-99), discussing the three enclosing structures of walls, says that within the first one stands the church of S. Stefano in Badia, wherefrom once came regular chimes telling the hours, but which is now in ill repair, as he knows from personal experience, because it was there that he listened to the lectures on Dante's poem given by his teacher, Giovanni Boccaccio.