From the source, “
When was the book of Job written? How do we know it was written then since we don’t know who wrote the book and when Job lived?
Top Ten Reasons Why We Believe the Book of Job was Written During the Time of the Patriarchs
1. Job lived 140 years after his calamities (42:16). This corresponds with the lifespans of the patriarchs. For example, Abraham lived 175 years.
5. Job’s daughters were heirs of his estate along with their brothers (Job. 42:15). This was not possible later under the Mosaic Law if a daughter’s brothers were still living (Num. 27:8).
7. The Book of Job includes no references to the Mosaic institutions (priesthood, laws, tabernacle, special religious days and feasts).
8. The name (sadday) is used of God 31 times in Job (compared with 17 times elsewhere in the Old Testament) and was a name familiar to the patriarchs.
9. Several personal and place names in the book were also associated with the patriarchal period. Examples include (a) Sheba – a grandson of Abraham, (b) Tema – another grandson of Abraham, (c) Eliphaz – a son of Esau, (d) Uz – a nephew of Abraham.
This source brings up some interesting details regarding the Book of Job. One of those details revolves around his daughter being heirs of his estate along with their brothers.