Commentary Par V 127-128

Dante's two questions addressed to Justinian will be answered in the next canto at [Par VI 1-27] and [Par VI 112-126].  His second question reflects his similar one to Piccarda ([Par III 64-66]).  Why is this spirit in so relatively low a sphere?  Dante may have forgotten Beatrice's instruction in the last canto ([Par IV 28-36]), which makes it plain that such heavenly gradation is only temporary.  Or he may have grasped the point that temporary presence in a planet is part of God's universal plan for his instruction and wants to know more.