p. 282
हे क्षत्रिय, अन्तवन्तः अन्तवतो लोकान् पितृलोकदेवलोकादीन् ते जयन्ति, नानन्तं स्वात्मभूतं परमात्मानं लोकं जयन्ति ।केन तर्ह्यनन्तलोकप्राप्तिरित्याशङ्क्याह—ज्ञानेन
In plain words
O Kṣatriya: "having an end" means worlds that end — the world of the ancestors, the world of the gods, all the rest of them. Those they win. What they do not win is the endless world, the supreme Self, which is their own Self. "Then how is the endless world reached?" — he raises the question himself, and answers: by knowledge.
Close to the Sanskrit
O Kṣatriya, 'having an end' — worlds that have an end, the world of the ancestors, the world of the gods and the rest: these they conquer. They do not conquer the endless world, the supreme Self which is one's own Self. 'By what, then, is the endless world attained?' — anticipating this doubt, he says: by knowledge.