मनःप्रसादः सौम्यत्वं मौनम् आत्मविनिग्रहः । भावसंशुद्धिर् इत्य् एतत् तपो मानसमुच्यते ॥

manaḥ-prasādaḥ saumyatvaṃ maunam ātma-vinigrahaḥ | bhāva-saṃśuddhir ity etat tapo mānasamucyate ||

Mental tapas: serenity of mind, kindliness, silence, self-restraint, and purity of motive/bhāva.

Word by word (3)
manaḥ-prasādaḥ saumyatvaṃ maunam ātma-vinigrahaḥ
— serenity/clarity of mind (manaḥ-prasāda = mind's clearness/brightness), gentleness/kindliness (saumyatva), silence/stillness (mauna), self-restraint/discipline of the self (ātma-vinigraha)
bhāva-saṃśuddhiḥ
— purity/complete-purification (saṃ-śuddhi = thorough purification) of motive/feeling/bhāva (bhāva = the inner state, emotion, intention, attitude) — not just clean action but clean intention
ity etat tapo mānasamucyate
— this indeed (ity etat) is called (ucyate) the tapas of mind (mānasa = mental/of the mind) — completing the triad: body (V14) + speech (V15) + mind (V16)

Serenity of mind, gentleness, silence, self-control, and purity of inner motive — this is called the austerity of the mind.

A modern analogy

Mental tapas is not meditation in a cave — it is the discipline of the inner life at all times. A mind that is genuinely serene (manaḥ-prasāda), gentle in its impulses (saumyatva), restrained in its reactions (ātma-vinigraha), and pure in its motivations (bhāva-saṃśuddhi) is performing continuous tapas every moment, regardless of what the body or speech is doing.

V16 completes the three-dimensional tapas definition (body V14, speech V15, mind V16). Mental tapas is the deepest level because all external action originates in mind. Bhāva-saṃśuddhi (purity of motive) is particularly significant — it means that even technically correct actions (vidhi-correct yajña, proper speech) can be tāmasic or rājasic if the bhāva is impure. This connects to the chapter's core insight (V3): yo yat-śraddhāḥ sa eva saḥ — you are your śraddhā, which is a quality of bhāva.

The five components of mental tapas form a progressive interior. Manaḥ-prasāda and saumyatva are the basic mental climate; mauna and ātma-vinigraha are the disciplines that maintain it; bhāva-saṃśuddhi is the deepest purification — reaching not just behavior but the motivational substrate. Shankaracharya emphasizes bhāva-saṃśuddhi as 'purity of nature' — the ātman's true disposition unclouded by rāga-dveṣa. This is the mental precondition for the three-fold pure tapas described in V17.

Public-domain translations (4) compare all →

Serenity of mind, good-heartedness, silence, self-control, purity of nature — this is called the mental austerity. [1]

Serenity of mind, kindliness, silence, self-control, honesty of motive — this is called the mental austerity. [4]

Cheerfulness of mind, placidity, silence, self-restraint, purity of heart — this is called the penance of the mind. [9]

Cheerfulness of mind, good-heartedness, silence, self-restraint, purity of thought — this is called the mental penance. [13]

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