अपाने जुह्वति प्राण प्राणेऽपानं तथाऽपरे। प्राणापानगती रुद्ध्वा प्राणायामपरायणाः॥
apāne juhvati prāṇa prāṇe'pānaṃ tathā'pare prāṇāpānagatī ruddhvā prāṇāyāmaparāyaṇāḥ
Meaning
There are some who practice controlling the vital energy and governing the subtle forces of prana and apana, thereby sacrificing their prana to apana, or their apana to prana.
English translation by Shri Purohit Swami (1935), public domain. Sanskrit text in the public domain. About Duvidha