And some commentators together with the compilers of later texts have gone to greater lengths in turning puñña into patti (merit)—a spiritual currency—which one should collect as much as possible.
In some Buddhist communities, this list has superseded the importance of “being refrained from akusala” and pushed Buddhists to a frenzy of ritualistic merry-making out of craving rather than the earliest idea of letting-go (nekkhamma) of craving. Also, these later texts turned the puñña into something can be given to another (a copy-paste). Therefore the list has "giving merit" and "rejoicing merit".
The karma cannot be transferred so does the resulting purity or impurity of. When I perceived a wholesome action done by another person, depending on my views and state of mind, there will be karma generated in me, but it's never the same karma of the 1st doer either in quantity or in quality.
[/quote]Evil is done by oneself, by oneself is one defiled.
Evil is left undone by oneself, by oneself is one cleansed.
Purity & impurity are one’s own doing.
No one purifies another.
No other purifies one.
~ Dhammapada 165
Thanks for your thoughtful reply. It gets straight at the heart of the matter, wbich is the same as what I was thinking. Correct me if I misunderstand your meaning, but to paraphrase, originally the Buddha taught that merit is basically the good that comes from keeping the precepts, which is another way of saying the fruit of kamma. It was 500 years later that the meaning of merit was expanded and modified into something beyond what the Buddha taught, that it is really an Abidhamma concoction..