Thank you, Bhikkhu Pesala,

I am familiar with this passage, and it seems to be close to what I
was looking for.

Here it says:
cattaarimaani bhikkhave acinteyyaani, na cintetabbaani; yaani
cintento
ummaadassa vighaatassa bhaagii assa.

Which I translate roughly as:
There are these four imponderables, monks, that are not to be
thought about; for one thinking about them would be one bestowed
with madness and vexation.

This came up in a discussion with some friends and we seem to
remember somewhere it being said that "one's head would explode",
but can't remember where. Is there somewhere else in the canon
where these imponderables are discussed more graphically?

John

--- In Pali@yahoogroups.com, "Bhikkhu Pesala" <pesala@...> wrote:
> Anguttaranikaaya, catukkanipaata, apa.n.nakavaggo, Acinteyyasuttam
(Ro 2.
> 80)
>
> cattaarimaani bhikkhave acinteyyaani, na cintetabbaani; yaani
cintento
> ummaadassa vighaatassa bhaagii assa. Katamaani cattaari?
Buddhaanama
> bhikkhave buddhavisayo acinteyyo, na cintetabbo, yam cintento
ummaadassa
> vighaatassa bhaagii assa. Jhaayissa ... Kammavipaako bhikkhave ...
> Lokacintaa bhikkhave na cintetabbo, yam cintento ummaadassa
vighaatassa
> bhaagii assa.