Khecarī Mudrā (Sanskrit, खेचरी मुद्रा) is a hatha yoga practice carried out by curling the tip of the tongue back into the mouth until it reaches above the soft palate and into the nasal cavity. In the full practice, the tongue is made long enough to do this with many months of daily tongue stretching and by gradually severing the lingual frenulum with a sharp implement over a period of months.
In the beginning stages and for most practitioners, the tip of the tongue touches the soft palate as far back as possible without straining, or is placed in contact with the uvula at the back of the mouth. Variant spellings include Khechari Mudra, Kecharimudra, and Kechari Mudra. Mudrā (Sanskrit, मुद्रा, literally "seal"), when used in yoga, is a position that is designed to awaken spiritual energies in the body.
The Buddhist Pali canon contains three passages in which the Buddha describes pressing the tongue against the palate for the purposes of controlling hunger or the mind (example), depending on the passage. However, there is no mention of the tongue being inserted into the nasopharynx. Khechari Mudra is to be practised when the practitioner is on a light, healthy diet, otherwise constipation tends to occur, as the prana or life energy needed to digest food does not adequately reach the lower chakras.
A hathayoga text, the Khecarīvidyā, states that khechari mudra enables one to raise Kundalini and access various stores of amrita in the head, which subsequently flood the body. Siva, in the same text, gives instructions on how to cut the lingual frenulum as a necessary prerequisite for the kechari mudra practice:
He should take a very sharp, well-oiled and clean blade resembling a leaf of the Snuhī plant and then cut away a hair's breadth [of the lingual frenulum] with it. After cutting, he should rub the cut with a powder of rock salt and black myrobalan. After seven days he should again cut away a hair's breadth... After six months the binding tendon at the base of the tongue is destroyed... Then, in six [more] months, after regular drawing out of the tongue, my dear, it reaches between the eyebrows... Licking with his tongue the supreme nectar of immortality [amrita] flowing there... the yogi should drink... and with a body as incorruptible as diamond, lives for 100,000 years.
A tantric Saiva text, the Mālinīvijayottaratantra, warns:
[If] his mouth fills with a slightly salty liquid that smells of iron then he should not drink it but spit it out. He should practice thus until [the liquid] becomes sweet-tasting.
Bhattacharyya defines Khecarī Mudrā as the "Yogic posture which bestows spiritual attainment and enables one to overcome disease and death." He explains that "Kha denotes brahman, and that power which moves (cara) as the kinetic energy of brahman is known (as) Khecarī." Singh defines Khecarī Mudrā as "the bliss of the vast expanse of spiritual consciousness, also known as divya mudrā or Śivāvasthā (the state of Śivā)." He further identifies it in a higher sense—with the end state of consciousness, and not just the physical posture used to achieve that end: "So Khecarī Mudrā in Śaiva āgama means a state of universal consciousness which is the state of Śiva."[a] Abhinavagupta, in his Tantraloka, states that all other mudras derive from khecarī mudrā, which he describes as "the stance of moving or flying through the void of the supreme consciousness." The practice is also mentioned in the Hatha Yoga Pradipika (III. 6-7).
Through the performance of Kechari Mudra, touching the tip of the tongue to the uvula, or "little tongue," (or placing it in the nasal cavity behind the uvula), that divine life-current draws the prana from the senses into the spine and draws it up through the chakras to Vaishvanara (Universal Spirit), uniting the consciousness with spirit.
According to Swami Kriyananda, "The assumption of this mudra helps to hasten the advent of deep spiritual states of consciousness." Swami Sivananda described Khecarī Mudrā as "the best of all Mudras."