The I-ni-pi ceremony ( lakota: ini- from inyan, rock + -pi, lodge), a type of sweat lodge, is a Lakota purification ceremony, and one of the Seven Sacred Rites of the Lakota people. It is an ancient and sacred ceremony of the Lakota people and has been passed down through the generations of Lakota.
The full ceremony is not taught to non-Lakotas, but in rough detail it involves an I-ni-pi lodge - a frame of saplings covered with hides or blankets. Stones are heated in a fire, then placed into a central pit in the lodge. Water is then poured on the stones to create hot steam. Traditional prayers and songs are offered in the Lakota language.
Those who have inherited and maintained these traditions have issued statements about the standards to be observed in the I-ni-pi. In the March 2003 meeting it was agreed among the spiritual leaders and Bundle Keepers of the Lakota, Dakota, Nakota, Cheyenne and Arapahoe Nations that:
I-ni-pi (Purification Ceremony): Those that run this sacred rite should be able to communicate with Tun-ca-s'i-la (our Sacred Grandfathers) in their Native Plains tongue. They should also have earned this rite by completing Han-ble-c'i-ya and the four days and four years of the Wi-wanyang wa-c'i-pi.
This also follows upon the decisions made at the Lakota Summit V, an international gathering of US and Canadian Lakota, Dakota and Nakota Nations, where about 500 representatives from 40 different tribes and bands of the Lakota unanimously passed a "Declaration of War Against Exploiters of Lakota Spirituality." The declaration was unanimously passed on June 10, 1993. Among other things, it specifies that these ceremonies are only for those of the Lakota, Dakota and Nakota Nations.
One concern about outsiders trying to perform these ceremonies is that, not only does it go against the express wishes of the traditional healers who have inherited these ceremonies, but that those who do not know how to do them properly have in some cases caused dehydration and heat stroke, resulting in injury and even deaths.