Gregory the Dialogist

Who, though I possessed any thing righteous, yet would I not answer, but I would make supplication to my Judge. For, as we have often said, all human righteousness is proved unrighteousness, if it be judged by strict rules. And so there is need of prayer following after righteousness, that this, which if sifted to the bottom might be brought down, may be firmly established in the mere pitifulness of the Judge. And when this is possessed fully by the more perfect sort, it is said that they possess a something of it. …

Morals on the Book of Job, Book IX ↗

Thomas Aquinas

Sometimes although one is not powerful or wise, he is still not afraid to argue with a judge because of the security of his conscience. But Job excludes this reason for disputing with God from his case when he says, "Even if I were somewhat just, I could not answer him at all," with God examining me in defense of my own justice, "but will rather ward off my judge by earnest prayer," not asking for justice, but for mercy. …

Commentary on Job ↗