Yoga Sutras of Patanjali · 3.42

कायाकाशयोः सम्बन्धसंयमाल्लघुतूलसमापत्तेश्चाकाशगमनम्॥४२॥

kāya-ākāśayoḥ sambandha-saṁyamāl laghu-tūla-samāpatteś cākāśa-gamanam

By sanyama on the relationship between the body and space, and by coalescing with the lightness of cotton fiber, movement through space arises.

— Yoga Sutras of Patanjali 3.42

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).