Paṭhamasamuddaninnasutta - translated by Bhikkhu Bodhi
“Bhikkhus, just as the river Ganges … sn.v.40 … whatever great rivers there are … all slant, slope, and incline towards the ocean, so too a bhikkhu who develops and cultivates the Noble Eightfold Path slants, slopes, and inclines towards Nibbāna.”