looking for citation, pīti and sukha of 4 jhānas compared to dying of thirst, seeing water in distance, and drinking it There's an excellent simile in the Theravada non canonical literature explaining the difference between piti and sukha in the first 3 jhanas, reminiscent of the lotus pond in this sutta MN 40. (citation?)

As I remember it:


Piti = you're in a desert, dying of thirst, as you're approaching oasis/pond, you realize there's water in the distance, that you're not going to die, and you're going to drink that water soon. The thrill and excitement of that is piti.
sukha = you've arrived at the oasis/pond, now you're drinking the water. The pleasure from actually drinking the water is sukha.


Three questions:


what is the citation of that piti sukha simile for the 4 jhanas from?
might this sutta, MN 40, be what inspired that simile for jhana piti/sukha differentiation? Should the words piti sukha appear in MN 40 lotus pond, but got lost in transmission?
What does the MN 40 lotus pond simile mean on its own terms, just for this sutta? What are the 4 directions referring to?


MN 40 excerpt here:
MN 40: what is the meaning of the lotus pond simile?
what is the citation of that piti sukha simile for the 4 jhanas from?
  


It's from the Visuddhimagga-Ch IV.100 (pg. 139):


  And wherever the two are associated, happiness is the contentedness at getting a desirable object, and bliss is the actual experiencing of it when got. Where there is happiness there is bliss (pleasure); but where there is bliss there is not necessarily happiness. Happiness is included in the formations aggregate; bliss is included in the feeling aggregate. If a man, exhausted31 in a desert, saw or heard about a pond on the edge of a wood, he would have happiness; if he went into the wood’s shade and used the water, he would have bliss. And it should be understood that this is said because they are obvious on such occasions.


.


  
  might this sutta, MN 40, be what inspired that simile for jhana piti/sukha differentiation? Should the words piti sukha appear in MN 40 lotus pond, but got lost in transmission?
  


Possibly. But notice the context is different between MN 40 and Vism IV.100. In MN 40, the lotus pond simile was used to illustrate the benefits of cultivating the Four Divine Abodes and how it benefits everyone; while the Vism's simile was for describing the Piti/Sukha absorption factors of the Jhanas concentration practices.


  
  What does the MN 40 lotus pond simile mean on its own terms, just for this sutta? What are the 4 directions referring to?
  


The Four Divine Abodes.