Yōga Sūtras
Yōga Sūtra 3.11
sarvārthataikāgratayōḥ kṣayōdayau cittasya samādhipariṇāmaḥ।
(Practice of) having single pointed attention at all times results in the reduction of arousal of consciousness, called - samādhi-pariṇāmaḥ (Effects-of-Samādhi).