Canto 1 - Boyhood
Bāla-kāṇḍa
Chapter 43: Gaṅgā Descends to the Earth
Text 1.43.42
तस्माज्जह्नुसुता गङ्गा प्रोच्यते जाह्नवीति च।
tasmāj jahnu-sutā gaṅgā procyate jāhnavīti ca
tasmāt = from that time; jahnu-sutā = Jahnu-sutā; gaṅgā = Gaṅgā; procyate = is known as; jāhnavi = Jāhnavī; iti = as; ca = and.
From that time, Gaṅgā is known as Jahnu-sutā and Jāhnavī.1
1 Both names mean “daughter of Jahnu.”