1“Mendicants, the Ganges river slants, slopes, and inclines to the east. In the same way, a mendicant who develops and cultivates the seven awakening factors slants, slopes, and inclines to extinguishment.

And how does a mendicant who develops the seven awakening factors slant, slope, and incline to extinguishment? It’s when a mendicant develops the awakening factors of mindfulness, investigation of principles, energy, rapture, tranquility, immersion, and equanimity, which rely on seclusion, fading away, and cessation, and ripen as letting go. That’s how a mendicant who develops and cultivates the seven awakening factors slants, slopes, and inclines to extinguishment.”

To be expanded for each of the different rivers as in SN45.91-102.

1"Seyyathāpi, bhikkhave, gaṅgā nadī pācīnaninnā pācīnapoṇā pācīnapabbhārā; evameva kho, bhikkhave, bhikkhu satta bojjhaṅge bhāvento satta bojjhaṅge bahulīkaronto nibbānaninno hoti nibbānapoṇo nibbānapabbhāro.

Kathañca, bhikkhave, bhikkhu satta bojjhaṅge bhāvento satta bojjhaṅge bahulīkaronto nibbānaninno hoti nibbānapoṇo nibbānapabbhāro? Idha, bhikkhave, bhikkhu satisambojjhaṅgaṁ bhāveti … pe … upekkhāsambojjhaṅgaṁ bhāveti vivekanissitaṁ virāganissitaṁ nirodhanissitaṁ vossaggapariṇāmiṁ … evaṁ kho, bhikkhave, bhikkhu satta bojjhaṅge bhāvento satta bojjhaṅge bahulīkaronto nibbānaninno hoti nibbānapoṇo nibbānapabbhāro"ti.

Yāva esanā pāḷi vitthāretabbā.

Gaṅgāpeyyālavaggo navamo.

2Cha pācīnato ninnā,
cha ninnā ca samuddato;
Dvete cha dvādasa honti,
vaggo tena pavuccatīti.