Heidegger's Bible Handbook: Job: Job, an Idumean King?

6. He was neither Jobab, nor the King of the Idumeans.

Those that think Job to be the same as Jobab make him the King of Idumea. Thus a great many of the ancients, relying upon Genesis 36:28. But, since that Job was not Jobab, that passage does not at all help them. And concerning his parents, wife, children, manner of life, restoration, age, and other things, which are related out of the ancients, Aristeas, Pseudo-Philo, the Chaldean and Greek Translators, and also Theodotion,[1] they do not deserve credit. What is proven out of undoubted Scripture is enough, that he was a man perfect and upright, fearing God and eschewing evil, גָּד֖וֹל מִכָּל־בְּנֵי־קֶֽדֶם׃, the greatest of all the men of the East, Job 1:1, 2, etc.

[1] Theodotion was a linguist and convert to Judaism, who translated the Hebrew Scripture into Greek in the middle of the second century AD. His translation appears to be an attempt to bring the Septuagint into conformity with the Hebrew text.