It is a bit long explanation why the concept of pure octads (suddhāṭṭhaka) seems absent in Tipitaka. It is definitely absent in the Sutta Pitaka. I will write about it at some point, but there are more pressing issues to be discussed right now.
- It is easier to proceed the other way, as I suggested above.
- Did you read the posts I recommended in my last comment above? Do you think there is insufficient evidence supporting the mental body (gandhabba) concept?