This śloka continues the specific meditation preparation that began in 6.10 and 6.11. First, Bhagavān taught the need for solitude, aloneness, discipline, freedom from binding desires, and non-possessiveness. Then He described the clean place and steady seat. Now He tells what the seeker should do after sitting on that seat.

Tatra means “there” — in that clean, sacred, secluded place, on the steady seat already prepared. This is important. Meditation is not being presented as a vague inner activity disconnected from life. The place has been prepared. The seat has been prepared. The body is now placed there. Only then does the work with the mind begin.

Upaviśya āsane means “having sat on the seat.” The seeker must physically sit. This sounds simple, but it is not trivial. The body has to be brought to one place and kept steady. A body that keeps moving, adjusting, checking, and reacting will keep the mind outward. Sitting is not merely physical placement; it is the first visible sign that the seeker is now withdrawing from outer activity.

Then Bhagavān says ekāgraṁ manaḥ kṛtvā — having made the mind one-pointed. Ekāgratā means single-pointedness. The mind generally runs in many directions: family, work, health, memory, plans, regrets, fears, conversations, possessions, and unfinished tasks. In meditation, the mind is to be gathered and directed toward one field.

For Vedāntic meditation, that field is not a random object. The mind must dwell on the teaching already received from śāstra and guru. Meditation is not blankness. It is not merely sitting with no thought at all. A totally blank mind may give rest, but it does not give spiritual assimilation. The mind must entertain the relevant thought connected with the Self: “I am the witness-consciousness,” “I am not the body-mind,” “I am asaṅga, unattached,” “I am pūrṇa, full.” Such thoughts help the knowledge enter the personality.

This is why mind preparation and teaching exposure are both important. If the seeker has not heard the teaching, what will he meditate upon? If the seeker has heard the teaching but the mind is scattered, the teaching will remain only as information. Meditation brings the teaching into the heart of the personality.

The next phrase is yatacittendriyakriyaḥ — one whose mental and sensory activities are restrained. The mind and senses are closely connected. The eyes want to look. The ears want to hear. The tongue wants to speak or taste. The hands want to move. The mind wants to comment, remember, plan, and react. If the sense doors are left wide open, the world enters the mind. If the mind keeps following every sensory contact, one-pointedness becomes impossible.

Therefore, the meditator must temporarily withdraw from unnecessary sensory activity. This does not mean damaging or hating the senses. It means giving them rest from their usual outward movement. The eyes may be gently closed or half-closed. Speech stops. The body becomes quiet. The phone is away. The mind is not allowed to chase every sound, smell, memory, or plan. The whole personality is brought under one direction.

Finally, Bhagavān says yuñjyāt yogam ātma-viśuddhaye — one should practice this yoga for the purification of the mind. Here ātma means the mind or inner instrument, not the pure Self. The pure Self does not need purification. Consciousness is ever pure. What requires purification is the mind: its restlessness, emotional burden, distraction, habitual self-judgment, insecurity, and binding reactions.

Therefore, this meditation is a means of antaḥkaraṇa-śuddhi, purification and integration of the inner instrument. It helps the mind become clear, subtle, steady, and fit for knowledge or fit for assimilation of knowledge.

This point is very important: meditation is not presented here as a shortcut that produces mokṣa directly. Nor is it meant for mystical entertainment. Its role is to purify, integrate, and steady the mind. When the mind is pure and one-pointed, śravaṇam and mananam become effective. After knowledge, nididhyāsanam helps the knowledge become assimilated. In both cases, the mind must become available.

Thus, 6.12 gives the actual inner discipline after the external setup. Sit on the prepared seat. Gather the mind. Restrain the mind and senses. Practice meditation for inner purification. This is the bridge between arranging the outer environment and entering real dhyānam.