Gregory the Dialogist

I am clean, and without spot of sin, and there is no iniquity in me, because He hath found complaints in me, therefore He hath counted me as His enemy, He hath placed my feet in the stocks, He hath guarded all my ways. And in answer to these words which he said blessed Job had spoken, he immediately states his own opinion.

Morals on the Book of Job, Book XXIII ↗

Thomas Aquinas

First, he had noted in the words of Job that he had said that he was immune from sin (13:6 and 16:18) and so he says, "I am clean," from the impurity of the flesh, "and without fault," caused by the sin of omission; "without stain," from grave sins which are against God like idolatry and other sins of this sort; "and there is no evil in me," which would cause me to wound my neighbors unjustly.

Commentary on Job ↗