One should retain until it is felt from the hair to the tips of the nails. Then one should exhale slowly through the left channel.

This verse describes the retention (kumbhaka) and exhalation (rechaka) of sūryabheda. The retention is maintained ākeśād ānakhāgrāt — “from the hair to the tips of the nails,” indicating that prāṇa must be perceived saturating every part of the body.

This description suggests that retention is measured not only in time but in depth of experience. When the practitioner feels prāṇa vibrating uniformly throughout the entire body, the retention has fulfilled its purpose.

The exhalation is performed savyanāḍyā — through the left channel (iḍā/candra). The repetition of śanaiḥ (slowly) emphasizes control. This pattern — inhaling through the right, exhaling through the left — is the basic structure of sūryabheda, designed to activate the solar principle and heat the system.