Yoga Sutras of Patanjali · 2.15

परिणामतापसंस्कारदुःखैर्गुणवृत्तिविरोधाच्च दुःखमेव सर्वं विवेकिनः ॥१५॥

pariṇāma-tāpa-saṁskāra-duḥkhair guṇa-vṛtti-virodhāc ca duḥkham eva sarvaṁ vivekinaḥ

To the discerning, all is suffering — because of the pain of change, the burning of anxiety, the impressions of past pain, and the constant conflict of the modifications of the gunas.

— Yoga Sutras of Patanjali 2.15

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).