Sakalya said: 'Whosoever knows that person (or god) whose dwelling (body) is the earth, whose sight (world) is fire, whose mind is light,—the principle of every (living) self, he indeed is a teacher, O Yagnavalkya.' Yagnavalkya said: 'I know that person, the principle of every self, of whom thou speakest. This corporeal (material, earthy) person, "he is he." But tell me, Sakalya, who is his devata (deity)?' Sakalya replied: 'The Immortal.'

In plain words: Sakalya says a real teacher must know the being whose home is the earth and the body. Yagnavalkya says he knows it: it is the physical person, the body. He asks Sakalya what deity rules it, and Sakalya answers, "The Immortal."