Yoga Sūtra Chapter Three verse 42

कायाकाशयोः संबन्धसंयमात् लघुतूलसमापत्तेश्चाकाश गमनम् ॥४२॥

kāya-ākāśayoḥ saṃbandha-saṃyamāt-laghu-tūla-samāpatteḥ ca-ākāśa-gamanam ||42||

From complete restraint of relationship of body and space
and unity with lightness and cotton,
travel through space.

kāya - the bodyākāśa - space; ether; subtle and ethereal fluid; sky, atmospheresaṃbandha - connection, binding or joining together, close union or associationsaṃyama - complete restraintlaghu - lightness; light in the stomach, easily digested; well, in good health; light, easy, not heavy or difficulttūla - cottonsamāpatti - coming together, unityca - andgamana - travel; going, moving, gait; obtaining, attaining