Yoga Sutras of Patanjali · 3.23
मैत्र्यादिषु बलानि॥२३॥
maitryādiṣu balāni
By sanyama on friendliness and the other (compassion, gladness, equanimity), the corresponding strengths arise.
— Yoga Sutras of Patanjali 3.23
Source: Sanskrit attributed to Patanjali (c. 2nd century BCE – 4th century CE). Public-domain English readings drawn from Swami Vivekananda's 'Raja Yoga' (1896) and Charles Johnston's 'The Yoga Sutras of Patanjali' (1912).