Canto 1 - Boyhood
Bāla-kāṇḍa
Chapter 24: The History of Sarayū
Text 1.24.8
कैलासपर्वते राम मनसा निर्मितं सरः।
ब्रह्मणा नरशार्दूल तेनेदं मानसं सरः॥
kailāsa-parvate rāma manasā nirmitaṁ saraḥ
brahmaṇā nara-śārdūla tenedaṁ mānasaṁ saraḥ
kailāsa-parvate = in the mountain Kailāsa at Kuvera’s residence; rāma = Rāma; manasā = with his mind; nirmitam = created; saraḥ = there is a lake; brahmaṇā = by Lord Brahmā; nara-śārdūla = O tiger among men; tena = therefore; idam = that; mānasam = is known as the Mānasa lake; saraḥ = lake.
O tiger among men Rāma, in the mountain Kailāsa at Kuvera’s residence, there is a lake created by Lord Brahmā with his mind. Therefore, that lake is known as the Mānasa lake.
That sound was actually caused by the confluence of a river. Considering that Rāma would then ask, “Which river?” in order to state that it is the Sarayū, Viśvāmitra begins to talk about the grandeur of Sarayū.