हठयोग प्रदीपिका (योगी स्वात्माराम - ज्योत्स्ना टीका सहित सटीक)

HAṬHAYOGAPRADĪPIKĀ 43:
35. Then rub [the part] with [a compound of]
powdered rock salt and Harītakī (yellow myrobalan).
Then after seven days, cut [again] to the extent of a
hair's breadth.
The compound should be rubbed on both morning and
evening. As salt is prohibited in the case of Yogin-s, they sub-
stitute the burnt powder of Khadira or the woody cassia. In the
text, salt is mentioned on the assumption that the Khecarī-mudrā
should be practised before the beginning of the Haṭha-yoga
practice. The cutting and medication should be done twice daily
for seven days. On the eighth day, the cut should be a little
deeper. And so on.
36. He should thus practise, gradually and skil-
fully every day for six months. In six months the mem-
brane which binds at the root of the tongue is severed.
37. Then turning back the tongue, it should be
made to enter the junction of the three [Nāḍī-s, i.e.
the cavity in the roof of the palate]. This is the Khecarī-
mudrā. It is [also] called VYOMACAKRA.
38. The Yogin who remains even for half a
kṣaṇa [i.e. for 24 minutes] with his tongue turned up-
wards is saved from poisons, disease, death and old age.
39. For him who knows the Khecarī-mudrā there
is no disease, death, [intellectual] torpor, sleep, hunger,
thirst, or clouding of the intellect.
40. He who knows the Khecarī-mudrā is not
afflicted by disease; not tainted by karman, and not
affected by Time.
The repetition of the results of Khecarī-mudrā is to impress
upon the reader its importance.