Commentary Par XXV 30

The Greek word 'basilica' is defined by Jacopo della Lana (DDP Lana.Par.XXV.29-30) as Domus regia (royal palace).  Benvenuto (DDP Benvenuto.Par.XXV.28-30) says that Beatrice is referring to the Church Triumphant (in the Empyrean, if it is now present here).