(Teachings of Lord Chaitanya, 1968 edition)
"The story involves the instruction of Sarvajna to a poor man who came to him to have his future told. When Sarvajna saw the horoscope of the poor man, he was at once astonished that the man was so poor, and he said to him, 'Oh, why are you so unhappy? I see from your horoscope that you have some hidden treasure left to you by your father. The horoscope, however, states that your father could not disclose this to you because he died in a foreign place. But now you can search out the hidden treasure left by your father and be happy.' This story is cited because the living entity is suffering due to his ignorance of the hidden treasure of his Father. The hidden treasure of the Father, Krishna, is Love of Godhead. In every Vedic Scripture the conditioned soul is advised to find that hidden treasure, which is known as Love of God. As is stated in the Bhagavad Gita, a conditioned soul, although he is the son of the Wealthiest—the Personality of Godhead—does not realize it; therefore the Vedic literature is given to him to help him search out his Father and his paternal property.
Sarvajna further advised the poor man: 'Don't try to dig on the southern side of your house to find the hidden treasure. If you do so, you'll be attacked by a poisonous wasp and you will be baffled in finding the treasure. The search should be to the eastern side where there is actual light—which is called devotional service, or Krishna Consciousness. On the southern side there is ritualistic performance of the Vedic Scripture, and on the western side there is speculative empiric knowledge, and on the northern side there is the Yoga system, or the meditational process for self realization.'
If somebody searches for his ultimate goal by the ritualistic process, he will be baffled. Such a process involves the performance of rituals under the guidance of the priest who takes money in exchange for service. A man thinks he will be happy by such performances, but actually they will not make him happy. Even he does gain some result therefrom, it is only temporary, and his material distresses will continue. So he will never become truly happy by such a ritualistic process. Instead, his material pangs increase more and more.
Similarly, digging for the hidden treasure on the northern side is compared with one's self-realization by dint of the meditational process. By the meditational process perfection is to think oneself One with the Supreme Lord. This merging into the Supreme by the living entity is something like the great serpent swallowing up the smaller serpent. From practical experience we see sometimes that a big serpent swallows up a smaller one, and the merging into the spiritual existence of the Supreme is analogous. The small serpent is, therefore, searching after perfection, and he is swallowed by the big serpent.
Digging on the western side is compared to the hidden treasure protected by Yakasa, the evil spirit that protects it. The idea is that hidden treasure can never be delivered by one who asks the favor of the Yakasa for attaining it. The result is that he will simply be killed. The Yogins who practice meditation are analogous to the small serpents. The speculative process of self-realization, or Jnana, is also suicidal in this case.
Actually, one has to dig for the hidden treasure from the eastern side, which is called devotional service in full Krishna Consciousness. That is the perpetual hidden treasure, and when one attains to that achievement, he becomes perpetually rich. One who is poor in devotional service and Krishna Consciousness is always in need of material gain. Sometimes he suffers the bites of poisonous things, and sometimes he is baffled; sometimes he follows the philosophy of monism and therefore loses his identity, and sometimes he is swallowed by the big serpent. By giving up all these things and becoming fixed in Krishna Consciousness, or devotional service to the Lord, he achieves the perfection of life."
(Teachings of Lord Chaitanya, Chapter 4)