हठयोग प्रदीपिका (योगी स्वात्माराम - ज्योत्स्ना टीका सहित सटीक)

36 HAṬHAYOGAPRADĪPIKĀ
and resembles the second kind of Prāṇāyāma. Kevala Kumbhaka
is the same as Kumbhaka Prāṇāyāma.
72. As long as one does not achieve Kevala Kum-
bhaka, one should practise Sahita.
The Sahita should be practised till the Prāṇa enters Suṣumnā,
which is known by a peculiar sound being produced in the Suṣumnā.
Then he should practise only ten or twenty Sahita Kumbhaka-s.
and increase the Kevala Kumbhaka-s to eighty.
72-73. Without exhalation or inhalation, when
the breath is retained with ease, this sort of Prāṇāyāma
is called Kevala Kumbhaka.
73-74. When this Kevala Kumbhaka has been
mastered without any exhalation or inhalation, there
is nothing unattainable by him in the three worlds.
74-75. He who is fully competent through this
Kevala Kumbhaka, through the control of breath,
obtains even the stage of Rāja-yoga. There is no doubt
about this.
75. Through Kumbhaka, the Kuṇḍalinī is
aroused; through arousing Kuṇḍalinī, the Suṣumnā
is free of all obstacles, and perfection in Haṭha-yoga is
obtained.
76. One cannot obtain perfection in Rāja-yoga
without Haṭha-yoga, nor [perfection] in Haṭha-yoga
without Rāja-yoga. So both should be practised till
perfection [in Rāja-yoga] is obtained.
77. At the end of the retention of breath in
Kumbhaka, the mind should be made free of objects.
By thus practising, the stage of Rāja-yoga is reached.