What is the textual source of the 4 infinitudes and the 6 coolnesses?
"There are these four unconjecturables that are not to be conjectured about, that would bring madness &amp; vexation to anyone who conjectured about them. Which four?

"The Buddha-range of the Buddhas[1] is an unconjecturable that is not to be conjectured about, that would bring madness &amp; vexation to anyone who conjectured about it.

"The jhana-range of a person in jhana...[2]

"The [precise working out of the] results of kamma...

"Conjecture about [the origin, etc., of] the world is an unconjecturable that is not to be conjectured about, that would bring madness &amp; vexation to anyone who conjectured about it.

"These are the four unconjecturables that are not to be conjectured about, that would bring madness &amp; vexation to anyone who conjectured about them."
https://www.accesstoinsight.org/tipitaka/an/an04/an04.077.than.html