In the eighteenth chapter, the Lord continues the narration of the dharmas (duties) of the different varnas. Silence (or measured speech),desirelessness and pranayama(breath control) are the three cudgels respectively for speech, body and mind.
One who does not wield these three cudgels cannot be called a recluse merely on the basis of his wielding a bamboo stalk. He should resort for alms to the persons of the four varnas,except those of reproachful conduct and visit only seven houses not identified in advance, and should remain contented with the food got from these houses alone. Realizing through force of reasoning that this entire manifested universe with its base in Sri Hari and conjoined with Rudra , Bharati and Mukhya Prana(the deities presiding over the mind, speech and vital air) to be fruitless and therefore not getting attached to it, he should constantly remember Sri Hari, the only Independent Entity.
Though sound of judgement, he should sport like a child(bereft of sense of honour and ignominy), though clever ,he should behave like a dullard.,though learned,he should rave like a madman in as much as he has none to please by his speech. He should not delight in debates and disputes over the import of the Vedas,nor take shelter of any side other than the one propagated by the Vedas. He should not be annoyed with anyone nor should he annoy anyone. With his mind fully controlled he should put up with the abuses and should never show disrespect to anyone.
The man of wisdom with the help of vision of the Lord(within himself) overcomes the tendencies to think and act against the Vedas. However due to the latent potencies of past karmas which last as long as the body lasts, should he indulge in some prohibited thinking or action, sins arising out of such actions are neutralized due to his jnana which finally leads him to liberation. To sum up, control of mind and the senses and harmlessness mainly constitute the Dharma of a mendicant recluse; enduring hardships prescribed by the shastras (tapas) and inquiry into the truth, of an anchorite (dwelling in the woods); protection of living beings and performance of the five great yajnas (sacrifices) of a householder; and rendering service to the preceptor, that of a celibate.
He who constantly worships the Lord through the performance of his duty as aforesaid, seeking no other reward (beyond pleasure of the Lord) begins to see the Lord in all created beings and attains firm devotion to the Lord before long. Thus ends the eighteenth chapter.