Yōga Sūtra 3.36

सत्त्वपुरुषयोरत्यन्तासङ्कीर्णयोः प्रत्ययाविशेषो भोगः परार्थत्वात्स्वार्थसंयमात्पुरुषज्ञानम्।

sattvapuruṣayōratyantāsaṅkīrṇayōḥ pratyayāviśēṣō bhōgaḥ parārthatvātsvārthasaṁyamātpuruṣajñānam।

[सत्त्व पुरुषयोः अत्यन्त असङ्कीर्णयोः प्रत्ययः अविशेषो भोगः परार्थत्वात् स्वार्थ संयमात् पुरुष ज्ञानम्।
sattva = sātvic; puruṣayōḥ = of the purusha; atyanta = in the end state; asaṅkīrṇayōḥ = unmixed; pratyayaḥ = awareness / the faith; aviśēṣō = not special; bhōgaḥ = experiences; parārthatvāt = for others; svārtha = oneself / selfish; saṁyamāt = by samyama; puruṣa = the purusha; jñānam = knowledge of;]

By samyama on (i) satva (and other qualities), (ii) the awareness of Purusha being unmixed and distinct in the end state, and (iii) the experiences of oneself being not special compared to others - one gains the knowledge of purusha, the being.