In an earlier post I wrote:

A messenger tells Job that all his children have been killed, yet later Job refers to his sons as though they are still alive: “I am loathsome to my children” (19:17 JPS). While some translations interpret this as “the children of my own mother” (ESV) or “my brothers” (NIV), the Hebrew (לבני בתני) literally reads “sons of my belly” and the JPS Tanakh translates this literally as a reference to Job’s actual physical children. Elsewhere in Job בתני is ambiguous, being used in reference to a man’s belly as well as a womb. Moreover, as it is in the first person (my belly/womb) then it is more likely to be a reference to his own children who came “from his loins” rather than his mother’s womb. In the prologue it doesn’t say Job’s children died, only that a messenger said his children had died (1:18-19), and if the literal meaning of לבני בתני is correct then it suggests that Job’s children were still alive later in the story.

In support of my assertion that Job referred to his livingchildren in 19:17 here is a comment by David Wolfers (Deep Things Out of Darkness [Grand Rapids: Eerdmans, 1995], 135f):

Job 19:17 ‘unmistakeably refers to the children as still living … The phrase פרי בטנך, the fruit of your body, occurs repeatedly in Deuteronomy, addressed to the community of Israel, with the force of the sense of “womb” attenuated as here to refer simply to the power of generation, without regard to gender e.g Deut 28:11”.

Wolfer refers to several other references in the speeches to Job’s “descendants” and allusions to his living children. Some translations attempt to resolve this apparent ‘contradiction’ by translating לבני בתני as “my brothers”, or similar, although the  expression “the sons of my womb/belly”,  is never used in the Hebrew Bible to refer to brothers. Trying to resolve a difficulty by mistranslating simply won’t do. Job has already referred to his brothers in verse 13, as well as his wife, servants and other relatives, and goes on to speak of the reactions of friends and young children. The most natural reading would be that Job is listing  all those with whom he has regular contact, including his children. To speak a second time of his brothers would be unnatural.

So what happened to his children? The best explanation, in my opinion, is that the poetry parts of Job were composed separately to the narrative prose in the ‘frame’ story. The poetry was written first and the prose was added later to give the debate a ‘setting’. It is not an historical record. This means that there are some conflicts between the poetry and the prose, but this was certainly of no concern to the writer (otherwise he could easily have corrected it) or to his audience. Consistency is probably more important to the modern reader than it was to an ancient one, and this may very well be because of our preconceived theological notions about what ‘inspiration’ means or demands of the text.