Commentary Inf V 18-19

Minos, seeing a rarity, to say the least -- a living man before him at the entrance to hell -- steals a moment from his incessant judgment to offer this warning. How kindly are his intentions? Most commentators seem to think he is the most 'humane' of the infernal demons, and even courteous to Dante. However, and as Padoan points out (DDP Padoan.Inf.V.19), his calling into question, albeit indirectly, the competence of Virgil as guide ('beware... whom you trust'), is evidently meant to unsettle Dante. He would obviously prefer not to have such visitors.