Chilla-nashini (Persian: چله نشینی) is a spiritual practice of penance and solitude, known mostly in Indian and Persian traditions. In this ritual a mendicant or ascetic attempts to remain seated in a circle practicing meditation techniques without food for 40 days and nights. The word 'chilla' is adopted from the Persian word 'chehel', meaning 'forty'. The nashini is the person who does the 40-day fast and remains seated in the circle of seclusion. It is (falsely) believed that those who try it but do not succeed usually die or suffer madness.
Chilla-nashini is a severe penance. A circle is drawn on the ground by the penitent's own hand; for forty days and nights he must not step out of the circle, he must forgo food, and avoid falling sleep. He must face whatever comes. Chilla-nashini is known to both Sufi and Vedantic ascetics.
The chilla is commonly performed in a solitary cell called chilla-khana.
In Music 
A practice similar to Chilla Nashini is also performed by "Hindustani Classical Music" practitioners at an advanced level. It is known as simply "Chilla". The musicians lock themselves up in a special room (chilla-khana) for forty days and practice their instrument severely. Special diet (often omitting meat and grains) is taken during this period (very little food is taken).Any contact to the outside world is avoided during this period.People try not to fall asleep at any cost, if necessary they will tie their hair to a noose at the ceiling. It is done to achieve a very high level of skill, that cannot be achieved due to normal regular practice.The Chilla details may differ from family (Gharana) to family.
People who have performed partial or complete nashini chillas 
Similar accounts in other cultures 
Gautama Buddha achieved enlightenment after fasting and meditating under the Bodhi Tree for forty days.However, enlightenment came after he broke his strict fasting and accepted some rice milk from a girl.
See also 
- The Path of Khalwati and Shabani
- Meher Prabhu, Bhau Kalchuri, Manifestation Inc. 1986, VOL I, p.129
- The Nothing and the Everything, Bhau Kalchuri, p.78
- Infinite Intelligence, Meher Baba, Sheriar Press, 2007
- Teachings of Hafiz: Translated by Gertrude Lowthian Bell
- Hafiz حافظ Biography
- Iran Chamber Society
- Bhau Kalchuri, Meher Prabhu: Lord Meher, The Biography of the Avatar of the Age, Meher Baba, Manifestation, Inc., 1986, p. 129.
- New Testament Bible, Matthew 4:2
- Deuteronomy 9:9
- "The angel of the Lord came back a second time and touched him and said, 'Get up and eat, for the journey is too much for you.' So he got up and ate and drank. Strengthened by that food, he traveled forty days and forty nights until he reached Horeb, the mountain of God." 1 Kings 19:7
- "In imitation of the great Jewish legislator on Sinai, he spent forty days on its summit in fasting and prayer, and other penitential exercises." Catholic Encyclopedia
- Sacred Destinations