'Yagnavalkya,' he said,' when the speech of this dead person enters into the fire, breath into the air, the eye into the sun, the mind into the moon, the hearing into space, into the earth the body, into the ether the self, into the shrubs the hairs of the body, into the trees the hairs of the head, when the blood and the seed are deposited in the water, where is then that person?' Yagnavalkya said: 'Take my hand, my friend. We two alone shall know of this; let this question of ours not be (discussed) in public.' Then these two went out and argued, and what they said was karman (work), what they praised was karman, viz. that a man becomes good by good work, and bad by bad work. After that Garatkarava Artabhaga held his peace.
In plain words: Artabhaga asks where a person really is once every part has gone back to nature: speech to fire, breath to wind, eyes to the sun, body to the earth. Yagnavalkya takes his hand and says they should discuss this privately. Alone, they agree the answer is karma (one's actions): a person becomes good by good deeds and bad by bad deeds.