A dhuni is (according to the dharmic religions such as Hinduism, Buddhism, Jainism, etc.) a sacred site represented as a cleft in the ground. This cleft is emblematic of the yoni or female vulva and generative organ. A dhuni therefore represents a site of worship dedicated to Shakti.
Honoring the dhuni
A dhuni is worshipped by spiritual intention and the kindling of a flame inside it. Suitable materials are offered to the dhuni and consumed by the heat or flame. This represents the eternal process of change and transformation on all levels of existence.
"Like a river, a dhuni is always changing. Each dhuni also has its own personality that is as much subject to moods as a person. The glow of the dhuni is both a receiver and a transmitter, and like a screen on which Rorschach-like images are projected, it delivers a code".
As the yoni is the nexus from which all manifest beings come into this world, the worship of the dhuni represents a sacred nexus for the path of return from the physical to spiritual level. This is an intentional process of inversion or return to our spiritual source. The dhuni is a sacred site and focal point for this form of spiritual exertion or sadhana.
Aside from the offering of sacred fuel to a dhuni, mantras are also offered, as well as the sounds of diverse musical instruments and ecstatic dance and gesture.
Although several cultures retain traditions of fire worship (out of which the zorastrianism is perhaps the most famous), a unique feature of the dhuni tradition is that it is the dhuni, the actual site itself which is considered sacred, not exclusively the fire kindled within it.
Shirdi Sai Baba
Sai Baba of Shirdi is certainly the most influential modern "Supersoul" to tend the Dhuni which he kept lit at that place until October 15, 1918 when he moved on. It is said that the same fire has been kept burning by Hindu devotees who were familiar with the notion of agnihotri or worship by offering fire. Much of the popularity of Joss sticks from India is due to this ancient tradition and this may have roots in the ceremonies referred to in the Mahabharata and also in the Ramayana. Many useful details can be found in the Shri Sai Satcharita which has been most beautifully translated into English language by Shri Nagesh Vasudev Gunaji, B.A., LL.B and which can be downloaded from various Shirdi Sai Baba web sites. A flame still burns at the Samadhi- Mandir although this may not be at the original site.
2. Kapilnath, Shri. Awakening the Nath Dhuni: Tantric Guidelines for Perfect Pyromania