I answered a very similar question to this a while ago here. That answer quoted a treatise that is very influential in East Asian Buddhism, namely the Madhyamakaśāstra. In the Madhyamakaśāstra, the author, Venerable Vimalākṣa, defines "prapañca" (translated here as "frivolous pondering") in two ways. From the linked post, abridged:
Because [Nirvāṇa] is characterized by quiet tranquility, it cannot be frivolously pondered as a frivolous pondering. Those are of two kinds. First is the argument from emotion, and the second is the argument from opinion. Via the middle, there are none of these two frivolous ponderings. Two frivolous ponderings (being) naught, there is neither agreement with nor dissent from. "Not another" and undifferentiated from itself, it is described as "reality."
I comment in the linked post:
The "argument from emotion" refers to argumentation rooted,
ultimately, in ignorance and suffering, as well as craving and greed.
We want to live forever. An "argument from emotion" to this effect
would be "Isn't it awful to believe that people just die? Surely it's
better (and makes me feel better) if ordinary persons, or maybe just
the Buddhas, were immortal." An "argument from opinion" refers to
personal theories as well as to secondary theses derived from primary
doctrines. An argument of this sort would be "The Buddha must exist
after death, because it is said that he doesn't not exist after
death."
I hope this is useful to you.