A Commentary on the Vinaya Piṭaka written by Buddhaghosa (Gv.59).
It was written at the request of Buddhasiri and was based on the Mahāpaccarī and the Kurundī Aṭṭhakathā.
See also Sāratthadīpanī. Sp.i.2; the reason for the name is given at Sp.i.201.