Canto 1 - Boyhood
Bāla-kāṇḍa
Chapter 44: Bhagīratha Delivers his Uncles
Text 1.44.14

प्लावयस्व त्वमात्मानं नरोत्तम सदोचिते।
सलिले पुरुषव्याघ्र शुचिः पुण्यफलो भव॥

plāvayasva tvam ātmānaṁ narottama sadocite
salile
puruṣa-vyāghra śuciḥ puṇya-phalo bhava

plāvayasva tvam = bathe; ātmānam = yourself; nara-uttama = O best of men; sadā = always; ucite = that is fit to be bathed in; salile = in the water [of Gaṅgā]; puruṣa-vyāghra = O tiger among men; śuciḥ = pure; puṇya-phalaḥ = the fruit of piety; bhava = become and attain.

O best of men, bathe yourself in the water [of Gaṅgā] that is always fit to be bathed in. O tiger among men, become pure and attain the fruit of piety.

Rivers other than Gaṅgā were not always fit to be bathed in because of dust.1

1 Other rivers had dust in them. Gaṅgā, coming from the heavens, was free from dust.