Valmiki Ramayana Yuddha Kanda Sarga 69 Shloka 23

धनुर्धरः wielding Bow, त्रिशिराः Trisira, रथम् chariot, आस्थाय taking seat, सविद्युदुल्कः attended by lightning, meteors light and rainbows, सैलाग्रे top of the mountain, सेन्द्रचापः sitting like leader, अम्बुदःइव like rain clouds, विरराज shone.

Wielding a bow and sitting like a leader in the chariot Trisira shone as if attended by lightning, meteors, light, and rainbows.