B.G 6.11 and 12
शुचौ देशे प्रतिष्ठाप्य स्थिरमासनमात्मनः। नात्युच्छ्रितं नातिनीचं चैलाजिनकुशोत्तरम् ॥११॥
तत्रैकाग्रं मनः कृत्वा यतचित्तेंद्रियक्रियः। उपविश्यासने युञ्ज्यात् योगमात्मविशुद्धये ॥१२॥
śucau deśe pratiṣṭhāpya sthiramāsanamātmanaḥ। nātyucchritaṁ nātinīcaṁ cailājinakuśottaram ॥11॥
tatraikāgraṁ manaḥ kr̥tvā yatacitteṁdriyakriyaḥ। upaviśyāsane yuñjyāt yogamātmaviśuddhaye ॥12॥
In a clean place, having established a steady seat for oneself, neither too high nor too low, made of cloth or deerskin, and kuśa grass; there, having made the mind one-pointed and controlling the activities of the senses, one should sit, engaging in the practice of Samādhi-Yoga for self-purification.
Gīta Bhāshya 6.11 and 12
'yogam yuñjyat' - practice of Samādhi-Yoga, i.e. Yoga to attain the equanimous state.
The word 'yogam yuñjyat' refers to the practice of Samādhi-Yoga, i.e. Yoga to attain equanimous state.