One imbued with interest in Brahman, with senses under control and assiduously attentive, begets knowledge. After gaining knowledge, he attains supreme peace before long.
Jnana is the knowledge about the Self. And Self is the presence which animates and activates the body. Why is it then rare and hard to gain this knowledge?
Krishna says lack of attention is the sole cause. People are careless in the matter. With sraddhā, assiduous application alone, one can penetrate within and know first-hand the inner presence. Everyone says ‘I’ right from the start till his body falls. Yet never is he prompted to probe and unearth what this ‘I’ is! What but inattention can be the cause of it?
With attention, abiding interest is also indispensable. Equally so, he must have enough sensory regulation. If with unrelenting attention, unabated interest and sensory regulation, one gains Self-knowledge, then he attains peace and quietitude before long, naturally. True spiritual attainment is not difficult or unduly rare. The rarity is always of seekers and their right striving!