Valmiki Ramayana Sundara Kanda Sarga 1 Shloka 82

अभ्रजालानि strings of clouds, पुनः पुनः again and again, प्रविशन् while entering, निष्पतंश्च and while coming out, प्रच्छन्नश्च hiding, प्रकाशश्च and shining, चन्द्रमाः इव like the Moon, लक्ष्यते was seen.

Entering into and emerging from the clouds, he looked like the Moon that appears and disappears (behind a bank of clouds).