Valmiki Ramayana Sundara Kanda Sarga 57 Shloka 8

अभ्रजालानि into the mass of clouds, प्रविशन् entering, पुनः पुनः again and again, निष्पतंश्च disappearing, प्रच्छन्नश्च covered by, प्रकाशश्च shining again, चन्द्रमाः like the Moon, लक्ष्यते was appearing.

With his exist and entrances into the mass of clouds, his appearances and disappearances among the clouds, he looked like the Moon.