Śrīmad-Bhāgavatam · Text 4.24.20
Who is speaking and story frame
ससमुद्रमुप विस्तीर्णमपश्यन् सुमहत्सर: ।
महन्मन इव स्वच्छं प्रसन्नसलिलाशयम् ॥ २० ॥
sa-samudram upa vistīrṇam
apaśyan sumahat saraḥ
mahan-mana iva svacchaṁ
prasanna-salilāśayam
While traveling, the Pracetās happened to see a great reservoir of water which seemed almost as big as the ocean. The water of this lake was so calm and quiet that it seemed like the mind of a great soul, and its inhabitants, the aquatics, appeared very peaceful and happy to be under the protection of such a watery reservoir.
Read Śrīla Prabhupāda's purport on Vedabase.io