ज्ञानं यथा न नश्येत नावकीर्येत वाङ्मन: ॥ ३९ ॥
jñānaṁ yathā na naśyeta
prāṇa-vṛttyā — with the mere functioning of his vital air; eva — even; santuṣyet — should be satisfied; muniḥ — a sage; na — not; eva — indeed; indriya-priyaiḥ — with things that gratify the senses; jñānam — consciousness; yathā — so that; na naśyeta — may not be destroyed; na avakīryeta — may not become disturbed; vāk — his speech; manaḥ — and mind.
A learned sage should take his satisfaction in the simple maintenance of his existence and should not seek satisfaction through gratifying the material senses. In other words, one should care for the material body in such a way that one’s higher knowledge is not destroyed and so that one’s speech and mind are not deviated from self-realization.
A wise man does not absorb his consciousness in the forms, flavors, aromas and sensations of material sense gratification, but rather accepts activities such as eating and sleeping simply to keep body and soul together. One must properly maintain one’s body by regulated activities of eating, sleeping, cleansing, etc., otherwise the mind will become weak, and one’s spiritual knowledge will fade away. If one eats too austerely, or if in the name of selflessness one accepts impure food, surely one loses control of the mind. On the other hand, if one eats food that is excessively fatty or rich there will be an unwanted increase in sleep and semen, and thus the mind and speech will be overwhelmed by the modes of passion and ignorance. Lord Kṛṣṇa has summarized the whole matter in Bhagavad-gītā by His statement yuktāhāra-vihārasya yukta-ceṣṭasya karmasu. One should moderately and intelligently regulate all of one’s bodily activities so that they are favorable for self-realization. This technique is taught by the bona fide spiritual master. If one is too austere or if one engages too much in sense gratification, self-realization is impossible.
It is the duty of a devotee of the Lord to avoid seeing any object as separate from Kṛṣṇa, because that is illusion. A gentleman will never try to enjoy the property of another gentleman. Similarly, if one sees everything in relation to Kṛṣṇa, there is no scope for material sense gratification. But if one sees material objects as separate from Kṛṣṇa, then one’s material enjoying propensity is immediately aroused. A human being must be intelligent enough to distinguish between preyas, or temporary gratification, and śreyas, permanent benefit. One may accept sense activity in a regulated, limited fashion so that one will be strong for serving Kṛṣṇa, but if one excessively indulges the material senses, one will lose one’s gravity and seriousness in spiritual life and act like an ordinary materialist. The ultimate goal, as stated here, is jñānam, or steady consciousness of the Absolute Truth, Lord Kṛṣṇa.