Commentary Par XIII 139

The foolish 'donna Berta e ser Martino' remind Carlo Grabher (DDP Grabher.Par.XIII.34-142) of what Dante says in Convivio (Conv.IV.v.9) about those vile beasts who desire to know what is known only to God.  A woman named Bertha had already enjoyed a role in Dante's displeasure with less-than-sophisticated writing; see De vulgari eloquentia (V.E.II.vi.5: 'Petrus amat multum dominam Bertam' (Peter loves Mistress Bertha a lot).