Commentary Par V 87

There is surprisingly much debate about the exact location of this brightness upon which Beatrice fastens her gaze.  Suffice it to say that, since they are still beneath the Sun, that is a possible terminus; but where the universe is brightest is where God is, the Empyrean.  Cf. the similar view expressed by John of Serravalle (DDP Serravalle.Par.V.85-87).