dhūmaḥ — smoke; rātriḥ — night; tathā — also; kṛṣṇaḥ — the fortnight of the dark moon; ṣaṭ-māsāḥ — the six months; dakṣiṇa-ayanam — when the sun passes on the southern side; tatra — there; cāndramasam — the moon planet; jyotiḥ — the light; yogī — the mystic; prāpya — achieving; nivartate — comes back.