Canto 3 -
Araṇya-kāṇḍa
Chapter 11: Rāma Goes to Agastya’s Āśrama
Text 3.11.11

तेनैवमुक्तो धर्मात्मा राघवेण मुनिस्तदा।
प्रभवं सरसः कृत्स्नमाख्यातुमुपचक्रमे॥

tenaivam ukto dharmātmā rāghaveṇa munis tadā
prabhavaṁ sarasaḥ kṛtsnam ākhyātum upacakrame

tena1 evam = was thus; uktaḥ = addressed; dharma-ātmā = of a dhārmika mind; rāghaveṇa = by Rāghava; muniḥ = the sage; tadā2 prabhavam = concerning the origin; sarasaḥ = of the lake; kṛtsnam = about everything; ākhyātum = to speak; upacakrame = began. 

Thus addressed by Rāghava, the sage, whose mind was dhārmika, began to speak about everything concerning the origin of the lake.

1 Technical note: tena rāghaveṇa.

2 Technical note: tadā ākhyātum upacakrame.