Yōga Sūtra 2.28

योगाङ्गानुष्ठानादशुद्धिक्षये ज्ञानदीप्तिराविवेकख्यातेः।

yōgāṅgānuṣṭhānādaśuddhikṣayē jñānadīptirāvivēkakhyātēḥ।

[योग अङ्गः अनुष्टानाद् अशुद्धिः क्षये ज्ञान दीप्तिः अविवेक ख्यातेः।
yōga = yōga; aṅgaḥ = the limbs; anuṣṭānād = by following; aśuddhiḥ = impurities from; kṣayē = diminishes; jñāna = knowledge; dīptiḥ = light of; avivēka = wrong knowledge; khyātēḥ = shines forth;]

By following the limbs of Yoga, the impurities arising out of wrong knowledge diminish; light of knowledge shines forth.