Mandukya Karika, verse 4.86

Sanskrit text, IAST transliteration and English translation

विप्राणां विनयो ह्येष शमः प्राकृत उच्यते ।
दमः प्रकृतिदान्तत्वादेवं विद्वाञ्शमं व्रजेत् ॥ ८६ ॥

viprāṇāṃ vinayo hyeṣa śamaḥ prākṛta ucyate |
damaḥ prakṛtidāntatvādevaṃ vidvāñśamaṃ vrajet || 86 ||

86. This (i.e., the realisation of Brahman) is the humility natural to the Brāhmaṇas. Their tranquillity (of mind) is also declared to be spontaneous (by men of discrimination). They are said to have attained to the state of sense-control (not through any artificial method as it comes quite natural to them. He who thus realises Brahman which is all-peace, himself becomes peaceful and tranquil.

Shankara Bhashya (commentary)

The humility of the Brāhmaṇas which is due to their realisation of their identity with the Self, is quite natural. This is (the real significance of) his humility. The tranquillity (of the mind which the Knowers of Brahman enjoy) is also natural and not induced by any artificial¹ means. Brahman is all peace and tranquility. Hence the Brāhmaṇas are said to have controlled their sense-organs (from pursuing the external objects). This is also the cause of the tranquillity of their nature. Having realised Brahman which is, by nature, all-peace the wise man attains to peace which is the characteristic of Brahman. That is to say, he becomes identical with Brahman.

Anandagiri Tika (glossary)

It has been stated in the previous Kārikā that the Knower of Brahman need no longer perform the daily ritualistic duties which are obligatory for ignorant persons. This Kārikā states that he need not undergo any Yogic or other practices in order to acquire humility, control of the senses and tranquillity of the mind. One who is established in Brahman, non-dual and all-peace, naturally and spontaneously acquires these virtues. The wise man realises that Brahman alone exists. Therefore his mind does not run after external objects, simply because they are non-existent for him. Realising Brahman everywhere, he does not show arrogance. Peace and tranquillity are quite natural for him. Yoga prescribes various artificial disciplines for acquiring these virtues. But he who clings to the Yogic practices, must be always on the alert lest his mind should be diverted to external objects. The Vedāntic method, depending upon discrimination, reveals everything as Brahman. Therefore for a Jñāni these virtues are quite spontaneous.

¹ Artificial, etc.—That is to say, the Yogic methods.