दर्शयामास चात्मानं समुद्रः सरितां पतिः।
समुद्रवचनाच्चैव नलं सेतुमकारयत्॥
darśayām āsa cātmānaṁ samudraḥ saritāṁ patiḥ
samudra-vacanāc caiva nalaṁ setum akārayat
darśayām āsa = showed; ca = and; atmānam = his original form; samudraḥ = the presiding deity of the ocean; saritām = Samudra, of the presiding goddesses of the rivers; patiḥ = the husband; samudra-vacanāt ca eva= on the request of Samudra; nalam = Nala; setum = a bridge; akārayat = had.
Samudra, the presiding deity of the ocean and the husband of the presiding goddesses of the rivers, [then] showed his original form [to Rāma].1 On the request of Samudra, [Rāma] had Nala build a bridge.
1 The original form of the ocean is Samudra, the presiding deity of the ocean. Humans and subhumans cannot see the original form of the ocean, especially in Kali-yuga. So is it with the sun, moon and other aspects of material nature presided over by demigods and demigoddesses.
The presiding deity of the ocean was the husband of the presiding deities of the rivers. It is hinted here that just as Kālīya appeared with his wives [and prayed to Lord Kṛṣṇa for His mercy], Samudra appeared along with his wives.