Gaṅgānadīādisutta  The Ganges River, Etc.

“Seyyathāpi, bhikkhave, gaṅgā nadī pācīnaninnā pācīnapoṇā pācīnapabbhārā;  “Mendicants, the Ganges river slants, slopes, and inclines to the east.
evameva kho, bhikkhave, bhikkhu cattāro iddhipāde bhāvento cattāro iddhipāde bahulīkaronto nibbānaninno hoti nibbānapoṇo nibbānapabbhāro.  In the same way, a mendicant who develops and cultivates the four bases of psychic power slants, slopes, and inclines to extinguishment.

Kathañca, bhikkhave, bhikkhu cattāro iddhipāde bhāvento cattāro iddhipāde bahulīkaronto nibbānaninno hoti nibbānapoṇo nibbānapabbhāro?  And how does a mendicant who develops the four bases of psychic power slant, slope, and incline to extinguishment?
Idha, bhikkhave, bhikkhu chandasamādhippadhānasaṅkhārasamannāgataṁ iddhipādaṁ bhāveti,  It’s when a mendicant develops the basis of psychic power that has immersion due to enthusiasm …
vīriyasamādhi …pe…  energy …
cittasamādhi …  mental development …
vīmaṁsāsamādhippadhānasaṅkhārasamannāgataṁ iddhipādaṁ bhāveti.  inquiry, and active effort.

Evaṁ kho, bhikkhave, bhikkhu cattāro iddhipāde bhāvento cattāro iddhipāde bahulīkaronto nibbānaninno hoti nibbānapoṇo nibbānapabbhāro”ti.  That’s how a mendicant who develops and cultivates the four bases of psychic power slants, slopes, and inclines to extinguishment.”

Dvādasamaṁ. 

Gaṅgāpeyyālavaggo catuttho. 

Tassuddānaṁ 

Cha pācīnato ninnā,  Six on slanting to the east,
cha ninnā ca samuddato;  and six on slanting to the ocean;
Dvete cha dvādasa honti,  these two sixes make twelve,
vaggo tena pavuccatīti.  and that’s how this chapter is recited.