प्राणेषु हृद्यन्तर्ज्योतिः पुरुषः स समानःसन्नुभौ लोकावनुसंचरति ध्यायतीवलेलायतीव स हि स्वप्नो भूत्वेमं लोकम-तिक्रामति मृत्यो रूपाणि ॥ ७ ॥
In plain words
Among the breaths that keep the body alive there is a person, a light burning within the heart. He is one and the same throughout, and he moves freely between two worlds, seeming to think, seeming to flicker and stir. Becoming a dream, he slips clean past this world, and past the shapes death wears too.
Close to the Sanskrit
Among the vital breaths, the person who is the light within the heart -- he, being the same in both, moves along both worlds, as if thinking, as if quivering. He, indeed, having become a dream, transcends this world and the forms of death.