B.G 17.16

मनः प्रसादः सौम्यत्वं मौनमात्मविनिग्रहः। भावसंशुद्धिरित्येतत् तपो मानसमुच्यते ॥१६॥

manaḥ prasādaḥ saumyatvaṃ maunamātmavinigrahaḥ। bhāvasaṃśuddhirityetat tapo mānasamucyate ॥16॥

[मनः (manaḥ) - mind; प्रसादः (prasādaḥ) - serenity; सौम्यत्वं (saumyatvaṃ) - gentleness; मौनम् (maunam) - silence; आत्म (ātma) - self; विनिग्रहः (vinigrahaḥ) - control; भाव (bhāva) - purity; संशुद्धिः (saṃśuddhiḥ) - purification; इति (iti) - thus; एतत् (etat) - this; तपः (tapaḥ) - austerity; मानसम् (mānasam) - mental; उच्यते (ucyate) - is called;]

(Serenity of mind, gentleness, silence, self-control, and purity of nature — this is called mental austerity.)

The serenity of mind, gentleness, silence, self-control, and purity of thought are considered as mental austerity.

Gīta Bhāshya 17.12

'saumyatvam' i.e. gentleness, means non-cruelty; 'maunam' i.e. silence means a contemplative nature. 'muni' i.e. sage is the one who realizes and experiences both childhood and wisdom; he has a determined view with deep insight on everything.

सौम्यत्वं अक्रौर्यत्वम्।

saumyatvaṁ akrauryatvam।

[सौम्यत्वं (saumyatvam) - gentleness; अक्रौर्यत्वम् (akrauryatvam) - non-cruelty;]

(Gentleness, non-cruelty.)

'saumyatvam' i.e. gentleness, means non-cruelty.

"अक्रूरः सौम्य उच्यते"

"akrūraḥ saumya ucyate"

[अक्रूरः (akrūraḥ) - Akrura; सौम्य (saumya) - gentle; उच्यते (ucyate) - is called;]

(Akrura is called gentle.)

"Not being cruel is said to be 'saumya', i.e. gentleness."

इति ह्यभिधानम्।

iti hyabhidhānam।

[इति (iti) - thus; हि (hi) - indeed; अभिधानम् (abhidhānam) - name;]

- declared thus in the dictionary.

मौनं मननशीलत्वम्।

maunaṁ mananaśīlatvam।

[मौनम् (maunam) - silence; मननशीलत्वम् (mananaśīlatvam) - contemplative nature;]

'maunam' i.e. silence, means contemplative nature.

"बाल्यं च पाण्डित्यं च निर्विद्याथ मुनिः॥"

"bālyaṁ ca pāṇḍityaṁ ca nirvidyātha muniḥ॥"

[बाल्यं (bālyam) - childhood; च (ca) - and; पाण्डित्यं (pāṇḍityam) - wisdom; च (ca) - and; निर्विद्याथ (nirvidyātha) - having realized; मुनिः (muniḥ) - sage;]

"The term 'muni' i.e. sage, is the one who realizes and experiences both childhood and wisdom."

इति हि श्रुतिः।

iti hi śrutiḥ।

[इति (iti) - thus; हि (hi) - indeed; श्रुतिः (śrutiḥ) - scripture;]

- indeed, stated thus in Vedic testimonial.

"एतेन हीदं सर्वं मतं यदनेन हीदं सर्वं मतं। तस्मान्मुनिः तस्मान्मुनिरित्याचक्षते।"

"etena hīdaṁ sarvaṁ mataṁ yadanena hīdaṁ sarvaṁ mataṁ। tasmānmuniḥ tasmānmunirityācakṣate।"

[एतेन (etena) - by this; हि (hi) - indeed; इदं (idaṁ) - this; सर्वं (sarvaṁ) - all; मतं (mataṁ) - determined view with deep insight; यद (yad) - which; अनेन (anena) - by this; हि (hi) - indeed; इदं (idaṁ) - this; सर्वं (sarvaṁ) - all; मतं (mataṁ) - determined view with deep insight; तस्मात् (tasmāt) - therefore; मुनिः (muniḥ) - sage; तस्मात् (tasmāt) - therefore; मुनिः (muniḥ) - sage; इति (iti) - thus; आचक्षते (ācakṣate) - they say;]

"By this, indeed, he has a determined view with deep insight on everything, by which he has a determined view with deep insight on everything. Therefore, he is called a sage, thus they say."

इति भाल्लवेयश्रुतिः।

iti bhāllaveyaśrutiḥ।

[इति (iti) - thus; भाल्लवेय (bhāllaveya) - of Bhāllaveya; श्रुतिः (śrutiḥ) - the teaching;]

- stated thus in Bhāllaveya Vedic testimonial.

कथं च अन्यथा मानसं तपः स्यात् ॥१६ ॥

kathaṁ ca anyathā mānasaṁ tapaḥ syāt ॥16॥

[कथं (kathaṁ) - how; च (ca) - and; अन्यथा (anyathā) - otherwise; मानसं (mānasaṁ) - mental; तपः (tapaḥ) - austerity; स्यात् (syāt) - would be;]

How else could there be mental austerity?

Gīta Tātparya 17.16

'maunam' i.e. silence, means deep reflection.

मौनं मननम् ॥१६॥

maunaṁ mananaṁ ॥16॥

[मौनम् (maunam) - silence; मननम् (mananam) - reflection;]

'maunam' i.e. silence, means deep reflection.