Rudra-prasava-varṇana
The Manifestation and Naming of Rudra / Nīlalohita
गोपायति दिवादित्यः प्रजा नक्तं तु चन्द्रमाः / एकरात्रौ समेयातां सूर्या चन्द्रमसावुभौ
gopāyati divādityaḥ prajā naktaṃ tu candramāḥ / ekarātrau sameyātāṃ sūryā candramasāvubhau
By day Āditya guards the creatures, and by night the Moon. In a single night—Amāvāsyā—Sun and Moon come together.