Patanjali Yoga Sutra — Abhyāsavairāgyābhyāṃ tannirodhaḥ||1.12||अभ्यासवैराग्याभ्यां तन्निरोधः||१.१२||

Sādhana (devoted practice) and detachment are the only two effective tools for controlling (above said five kinds of) mental modifications or thought waves.

Thus, whatever might be the kinds of mental modifications, they can be controlled by devoted practice and detachment. Dual (Dvivacana) Instrumental Case (vairāgyābhyāṃ) is used here because abhyāsa and vairāgya are two instruments with which nirodhaḥ (control) of mental modifications is possible.

When Arjuna expresses his apprehension and inability to control the mind, similar view is expressed by Bhagavān.

असंशयं महाबाहो मनो दुर्निग्रहं चलम्।

अभ्यासेन तो कौन्तेय वैराग्येण च गृह्यते॥गीता ६.३५॥

asaṁśayaṁ mahābāho mano durnigrahaṁ calam.

abhyāsena to kaunteya vairāgyeṇa ca gr̥hyate॥Gītā 6.35॥

Mighty armed Arjuna! Undoubtedly the mind is oscillating and very difficult to be brought under one’s own control. However, Kaunteya, it can be controlled by detachment (from worldly enjoyments — vairāgyeṇa) and unbroken sādhana (persistent practice — abhyāsena).

The word ‘abhyāsena tu kaunteya’ used by Bhagavān is very important here. It is being totally dedicated to one’s practice. One should have a complete commitment towards one’s own practice. viśvamitra ṛṣi wanted to achieve through tapas, what vasiṣṭha Maharṣi had achieved and his rigorous commitment till he becomes a Maharṣi is worth remembering by any spiritual sadhakās.

In Sādhana Pāda, Patañjali Maharṣi has very elaborately explained the Sādhana mārga (Steadfast Repetition Path) through his ‘Eight-Fold Philosophy of Yoga’ called ‘Aṣṭāṅga Yoga’. They are: Yama, Niyama, āsana, Prāṇāyāma, Prathyāhāra, Dhāraṇa, Dhyāna and samādhi. The first two limbs are called ‘Adhikāra Yoga (that which gives us right or power)’, the next three limbs are called ‘bahiraṅga (External) Yoga’, which is ‘Body-centered’ sādhana, and the last three limbs are called ‘antaraṅga (Internal) Yoga’, which is ‘God-centered sādhana. (You will read more on Sādhana (Dedicated Repetition) in the next chapter).

Then what is Vairāgya (Detachment)? It is nothing but renunciation of all those mundane or worldly things (painful or pleasurable, good or bad) which affect his Sādhana (resolute repetition) in one’s endeavor to salvation.