That is an interesting observation.
- However, I don’t think they are the same.
- We may have kamma bija from far back, many eons back waiting to bring their kamma vipaka.
- However, we have “upadana” for sensory inputs that come to us in this life, some as strong vipaka but others just because we have this physical body that is open to a multitude of sensory inputs.
- Of course, there can be some correlation between the two.
P.S. They are definitely not the same.
For example, kammic energy associated with a past kamma is going to be there in vinnana dhatu until one of the following two happens: (i) it brings vipaka and exhausts all that energy, or (ii) it does not get to deliver vipaka and the energy fades away on its own, with time.
When someone attains Arahathood, all upadana go away, but the energies of many kamma done in the past are still there. Some kamma bija can bring their vipaka until the Arahant’s physical body dies, i.e., until attaining Parinibbana.
- For example, when Ven. Angulimala attained Arahanthood his upadanakkhandha completely vanished. But he was subjected to some abuse (there are accounts in Tipitaka saying when kids throw stones, some of them would automatically come and hit Ven. Angulimala; kids were not trying to hit him. So, many days, he would return from alms round bleeding.)
It is good to think about these issues. That is when we can put our knowledge to work. This is real vipassana!