Albert Barnes Commentary Job 42:10

"And Jehovah turned the captivity of Job, when he prayed for his friends: and Jehovah gave Job twice as much as he had before." — Job 42:10 (ASV)

And the Lord turned the captivity of Job - this means He restored him to his former prosperity. This type of language is taken from the concept of restoration to one's country and home after being a captive in a foreign land.

This language is often applied in the Scriptures to the return of the Jews from their captivity in Babylon, and some writers have used it as an argument to show that Job lived after that event. But this conclusion is unwarranted.

The language is so general that it could be taken from the return from any captivity and is language that would naturally be used in the early periods of the world to denote restoration from calamity. It was common in the earliest ages to take captives in war to the land of the conqueror, thereby desolating a land by the removal of its inhabitants; and so it would be natural to use language describing their return to denote a restoration from any great calamity to former privileges and comforts.

This is undoubtedly its meaning as applied to the case of Job. He was restored from his series of protracted trials to a state of prosperity.

When he prayed for his friends - or, after he had prayed for his friends. It is not necessarily implied that his praying for them had any particular effect in restoring his prosperity.

Also the Lord gave Job twice as much as he had before - The marginal note reads, “added all that” had been to “Job unto the double.” The margin is a literal translation, but the meaning is the same. It should not be understood that this occurred at once, for many of these blessings were bestowed gradually. Nor should we understand it literally in every respect, as he had the same number of sons and daughters as before; however, it is a general declaration and was true in all essential respects.