Gregory the Dialogist

But oh that God would speak with thee, and open His lips unto thee! For man by himself speaks to himself when in all that he thinks he is not withdrawn by the Spirit of the Divine Being from the sense of carnal wisdom; when the flesh puts forth a sense, and inviting the mind as it were to the understanding of it, sends it forth abroad. And hence 'Truth' saith to Peter, who was still full of earthly notions, For thou savourest not the things that be of God, but the things that be of men. …

Morals on the Book of Job, Book X ↗

Thomas Aquinas

However, one should be careful to note that since sin is a turning aside from the law of God, one cannot know if something is a sin or its magnitude, if one does not know the law of God for "The straight line is the judge of both itself and the crooked line." So since Job said he was free from sin or he had not sinned as gravely as he was punished, Sophar understood from this that Job did not perfectly understand the law of God. …

Commentary on Job ↗