Let's start with "time period in which the old testament was composed"
When was that exactly? I believe the oldest extant versions are from around 300 AD. We have a rough idea of when certain books might have been written, but that is open to debate, and strong arguments have been made that put the origin of certain parts of these books centuries apart. Even the composition of a 'canonical' version of these books collections is not really clear before a certain point that is several centuries removed from the time in which we think they might have been originally written.
Different books or even different parts of a book (even what constitutes a 'book' in the old or new testament is not well defined for any given time period before a certain point from when we have some evidence of a certain standardization at a certain place - which doesn't even mean all traditions everywhere using these books follow that same standard from that point onward) might have been written at times centuries apart and might have originated in different cultures.
My point is, sweeping statements about customs and practices of specific societies as they were between one and three millennia ago is very hard to make. Even something like "the people who wrote this book clearly practiced primogeniture" is packed with lots of assumptions. And if we could know that a certain part of some scripture was from a definite time period and originally written in a certain language... who wrote it? Where? What was the legal system there?
Take another example, a period and people we have a lot of data about: in XVII century England, for example, primogeniture and entail were standard... for the elite. Not for the middle class. You see what I'm getting at?
Put simply, what I meant with my previous comment was: we have literally no idea if the people who wrote these supposed genealogies in Exodus were in fact practicing these inheritance legal forms you mentioned.
When was that exactly? I believe the oldest extant versions are from around 300 AD. We have a rough idea of when certain books might have been written, but that is open to debate, and strong arguments have been made that put the origin of certain parts of these books centuries apart. Even the composition of a 'canonical' version of these books collections is not really clear before a certain point that is several centuries removed from the time in which we think they might have been originally written.
Different books or even different parts of a book (even what constitutes a 'book' in the old or new testament is not well defined for any given time period before a certain point from when we have some evidence of a certain standardization at a certain place - which doesn't even mean all traditions everywhere using these books follow that same standard from that point onward) might have been written at times centuries apart and might have originated in different cultures.
My point is, sweeping statements about customs and practices of specific societies as they were between one and three millennia ago is very hard to make. Even something like "the people who wrote this book clearly practiced primogeniture" is packed with lots of assumptions. And if we could know that a certain part of some scripture was from a definite time period and originally written in a certain language... who wrote it? Where? What was the legal system there?
Take another example, a period and people we have a lot of data about: in XVII century England, for example, primogeniture and entail were standard... for the elite. Not for the middle class. You see what I'm getting at?
Put simply, what I meant with my previous comment was: we have literally no idea if the people who wrote these supposed genealogies in Exodus were in fact practicing these inheritance legal forms you mentioned.