Gregory the Dialogist

Lo, these ten times ye confound me. On enumerating the successive times of the speeches of Job's friends, we learn that as yet they had spoken but five times. But for this reason, that he had five times heard rebukes from them, and five times himself replied to their rebukes, he says that he had been ten times confounded; because both herein, viz. that he had been causelessly reproached, he suffered deeply, and in this, that he uttered words of instruction to those that gave no ear, he underwent confusion. …

Morals on the Book of Job, Book XIV ↗

Thomas Aquinas

It is tolerable if someone speaks against his own friend once, but if the man says the same things over and over he seems to be firmly established in malice, and so he then says, "Behold! You have confused me ten times," both by speaking yourselves and by listening to me with some anger. Before this present response, Job is found to have spoken five times if we begin from when he said, "Cursed be the day I was born." (3:13) and the friends are found to have answered him five times. …

Commentary on Job ↗