B.G 2.53

श्रुतिविप्रतिपन्ना ते यदा स्थास्यति निश्चला। समाधावचला बुद्धिस्तदा योगमवाप्स्यसि ॥२-५३॥

śrutivipratipannā tē yadā sthāsyati niścalā। samādhāvacalā buddhistadā yōgamavāpsyasi ॥2-53॥

[ श्रुति विप्रतिपन्ना ते यदा स्थास्यति निश्चला। समाधौ अचला बुद्धिः तदा योगम् अवाप्स्यसि ॥
śruti vipratipannā = special knowledge of Vēdas; tē = your; yadā = when; sthāsyati = gets stationed; niścalā = without movement; samādhau = in equanimity; acalā = steady; buddhiḥ = intellect; tadā = then; yōgam = Yōga; avāpsyasi = you will attain;]

When your intellect gets stationed in the special knowledge of Vēdas without waver, then having a steady-equanimous-state, you will attain Yōga.

Gīta Bhāshya 2.53

When the intellect grasps the certain knowledge of Vēdas decisively, the mind becomes unwavering and attains Yōga.

तदेव स्पष्टयति - श्रुतिविप्रतिपन्नेति।

tadēva spaṣṭayati - śrutivipratipannēti।

[tadēva = same is; spaṣṭayati = clarified; śrutivipratipannēti = in 'śrutivipratipannā' verse;]

Same (right understanding of Vēdas) is clarified futher in 'śrutivipratipannā' verse.

पूर्वं श्रुतिभिः वेदैः विप्रतिपन्ना विरुद्धा सती यदा वेदार्थानुकूलेन तत्त्वनिश्चयेन विपरीतवाग्भिरपि निश्चला भवति, ततश्च समाधौ अचला, ब्रह्मप्रत्यक्षदर्शनेन भेरीताडनादावपि परमानन्दमग्नत्वात्, तदा योगं अवाप्स्यसि उपायसिद्धो भवसीत्यर्थः ॥५३॥

pūrvaṁ śrutibhiḥ vēdaiḥ vipratipannā viruddhā satī yadā vēdārthānukūlēna tattvaniścayēna viparītavāgbhirapi niścalā bhavati, tataśca samādhau acalā, brahmapratyakṣadarśanēna bhērītāḍanādāvapi paramānandamagnatvāt, tadā yōgaṁ avāpsyasi upāyasiddhō bhavasītyarthaḥ ॥53॥

[pūrvaṁ = previously; śrutibhiḥ = 'shritu' means; vēdaiḥ = i.e. Vedas; vipratipannā = 'vipratipannā' means; viruddhā satī = opposed to; yadā =when; vēdārthānukūlēna = in line with the Vedas; tattvaniścayēna = from its decisive knowledge on the principles; viparītavāgbhirapi = even from contradictory appearing statements; niścalā bhavati = he becomes unwavering; tataśca = from that; samādhau = obtained equanimity; acalā = is without wavering; brahmapratyakṣadarśanēna = by direct perception of the lord, Brahman; bhērītāḍanādāvapi = even by the beating of the drum; paramānandamagnatvāt = is immersed in supreme bliss, tadā yōgaṁ avāpsyasi = then you will attain yoga; upāyasiddhō = the practice/solution is perfected; bhavasītyarthaḥ = becomes, is the meaning;]

'shruti' means Vedas. 'vipratipannā' means opposed to. When the knowledge that was previously opposed to Vedas comes to decisive understanding of its principles in line with the Vedas, in spite of statements that appear contradictory, then it becomes unwavering. From such wisdom, he obtains an equanimous state (smādhi) and becomes steady. In such a state, he is unaffected even by the beating of the drum as he is immersed in supreme bliss by direct perception of the Brahman. When such a practice is perfected, you will attain Yōga - is the meaning.