Yōga Sūtra 3.41

समानजयाज्ज्वलनम्।

samānajayājjvalanam।

[समान जयात् ज्वलनम्।
samāna = life force that balances (samāna); jayāt = mastery over; jvalanam = radiance, effulgence;]

By mastery over the life forces that balances (samāna) one becomes radiant.