chandhra sūrya (moon and sun) —

moon and sun —

starting with chandhra (moon) and ādhithya (sun) —

 being chandhra and sūrya —

 having great radiance —

the twin sources of radiance, viś., divine chakra and divine conch —

divine disc and divine conch which appear like sūrya (sun) and chandhra (moon) —

chandhra (moon) and ādhithya (sun), in vyashti srushti stage (subsequent variegated creation) (since having them as ṣarīra (body), they can be said as him) —

churning that manthara mountain (churning the ocean) such that the radiant moon, sun, sky and other lustrous entities spun around with him —