Yoga Sutras of Patanjali · 2.32

शौचसंतोषतपःस्वाध्यायेश्वरप्रणिधानानि नियमाः ॥३२॥

śauca-saṁtoṣa-tapaḥ-svādhyāyeśvara-praṇidhānāni niyamāḥ

The five niyamas are: purity, contentment, austerity, self-study, and surrender to the Lord.

— Yoga Sutras of Patanjali 2.32

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).