Amritapana literally means the imbibing of amrita or nectar or elixir of life. By doing this, one is supposed to become immortal. The word amritapana is also used in the context of final beatitude. Performance of penance or the practice of Yoga washes away one’s sins and leads to final beatitude (tapaa kilbisam hanti vidyayamritamasnute).
In a particular mudra (pose) of Hatha Yoga, called khichari mudra,
the elongated tongue is turned back upwards and its tip penetrates the upper
cavity near the pharynx. It is claimed that the amrita which continuously pours
down in the brahma-randhra is thus taken by the tip of the tongue. Meditation
with such amritapana brings immortality to the yogi.
The most famous story of amritapana is associated with the
Samudra manthan or churning of the ocean episode in the Puranas. On the directions
of Bhagavan Srihari Vishnu, the sap of amrita (immortality) was churned out of the
ocean by the devas and demons. After getting the amrita, a struggle followed between
the two sides to acquire the same. Bhagavan Vishnu took the form of Mohini to distribute
the amrita and requested them to sit in two rows. The devas sat in one row and
the asuras in another. But the asura Rahu stood up quietly and sat in the row
meant for devas and got a share of the amrita. On realizing the slip, Bhagavan
Vishnu cut Rahu’s head, but the head and trunk both remained alive in two
parts, as Rahu and Ketu.