In plain words
The poet, to the Lord: O you whose colour is the dark sea! The serpent [Ādiśeṣa], whose thousand poisonous mouths and two thousand eyes pour out fierce flame, who never parts from you, delightful in form and abundant in radiance, his dense beauty gathered above you as a canopy, lies spread as your couch on the waters of the [milky] ocean: what is it for, this sleep of yours upon him?