Adam Clarke on Job 42:16

After this lived Job a hundred and forty years - How long he had lived before his afflictions, we cannot tell. If we could rely on the Septuagint, all would be plain, who add here, Τα δε παντα ετη εζησεν, διακοσια τεσσαρακοντα; "And all the years that Job lived were two hundred and forty." This makes him one hundred years of age when his trial commenced. Coverdale has, After this lyved Job forty yeares, omitting the hundred. So also in Becke's Bible, 1549. From the age, as marked down in the Hebrew text, we can infer nothing relative to the time when Job lived. See the subscription at the end of the Arabic.