मनःप्रसादः सौम्यत्वं मौनमात्मविनिग्रहः।
17.16 Tranillity of mind, gentleness, reticence, withdrawal of the mind, purity of heart,-these are what is called mental austerity.
17.16 Serenity of mind, viz., absence of wrath etc., practice of benevolence, viz., the direction of the mind for the good of others, silence, viz., contorl of speech by the mind; self-control, viz., focusing the activity of the mind on the object of contemplation; purity of mind, viz., absence of thought about subjects other than the self - these constitute the austerity of the mind.
Manahprasaadah saumyatwam maunamaatmavinigrahah; Bhaavasamshuddhirityetat tapo maanasamuchyate.
manaḥ-prasādaḥ—serenity of thought; saumyatvam—gentleness; maunam—silence; ātma-vinigrahaḥ—self-control; bhāva-sanśhuddhiḥ—purity of purpose; iti—thus; etat—these; tapaḥ—austerity; mānasam—of the mind; uchyate—are declared as