'Whosoever, O Gargi, without knowing that Akshara (the imperishable), offers oblations in this world, sacrifices, and performs penance for a thousand years, his work will have an end. Whosoever, O Gargi, without knowing this Akshara, departs this world, he is miserable (like a slave). But he, O Gargi, who departs this world, knowing this Akshara, he is a Brahmana.'

In plain words: Yagnavalkya says that someone who does rituals and hard spiritual practice for a thousand years without knowing the Imperishable gains only results that run out. Whoever dies without knowing it is pitiable. But whoever dies knowing it is truly wise, a true Brahmana.