'A diver-bird (Madgu, meant for Prâna) will declare to you another foot of Brahman.' (After these words of the Hamsa), Satyakâma, on the morrow, drove the cows onward. And when they came towards the evening, he lighted a fire, penned the cows, laid wood on the fire, and sat down behind the fire, looking toward the east.

In plain words: The swan tells Satyakama that a diver-bird will teach him the next part about Brahman, the ultimate reality behind everything. The next day Satyakama drives his teacher's cows on, and at evening he makes a fire, pens the cows, and sits facing east.