Pranayama three types, rechaka, pooraka, and kumbhaka.
Pranayamas tridha prokto rechapurakakumbhakaih /
Sahitah kevalascheti kumbhako dvividho matah// (Chapter -2, Verse 71).
Pranayama is said to be of three types: exhalation (rechaka), inhalation (pooraka), and retention (kumbhaka). Kumbhaka is again of two types: connected sahita and unconnected kevala. (Chapter -2, Verse 71).
Yavat kevalasiddhih syat sahitam tavad abhyaset/
Rechakam purakam muktva sukham yadvayudharanam//(Chapter -2, Verse 72).
Till attain perfection in kevala kumbhaka, sahita kumbhaka has to be practiced. When you are freed of inhalation/exhalation then the breath/prana is ceased spontaneously. (Chapter -2, Verse 72).
Pranayamoa yam ityuktah sa vai kevalakumbhakah/
Kumbhake kevale siddhe rechapurakavarjite//(Chapter -2, Verse 73).
Perfection of isolated holding is freedom from inhalation and exhalation process. This pranayama spoken of is verily kevala kumbhaka. (Chapter -2, Verse 73).
Na tasya durlabham kimchittrishu lokeshu vidyate/
Saktah kevalakumbhena yatheshtam vayudharanat//(Chapter -2, Verse 74).
Nothing in the three worlds of existence is unobtainable by him who has mastery over kevala kumbhaka and can hold the breath as desired time. (Chapter -2, Verse 74).