Hmmmm.

1. You’re making the point that social mores shift over time. I’d say that’s rather obvious and unarguable.
2. The original poster, however, was *not* making the point that social mores shift over time; he was making the point that a particular religious (not social) more doesn’t exist in the Bible at all.
3. My response to that was essentially “I disagree, but it doesn’t really matter if it’s in the Bible or not”, because aside from a few rather noisy evangelical Protestant groups, Christians do not believe that the Bible is the only source of received truth.

So, forgive me if I’m still struggling to understand why my post brought your point to mind.