Theophylact of Ohrid — as excerpted in the Catena Aurea on Luke 18:9-14

“Pride also beyond all other passions disturbs the mind of man. And hence the very frequent warnings against it. It is moreover a contempt of God; for when a man ascribes the good he doth to himself and not to God, what else is this but to deny God? For the sake then of those that so trust in themselves, that they will not ascribe the whole to God, and therefore despise others, He puts forth a parable, to shew that righteousness, although it may bring man up to God, yet if he is clothed with pride, casts him down to hell.”