question: what is the stove?
answer: the highest level elixir method uses the “Shen” (consciousness) as the stove, the “Xing” (natural consciousness) as the medicine and being set as fire.
the middle level elixir method uses the “Shen” as the stove, the Qi as medicine, and the sun as fire. The lowest level elixir method uses the body as the stove, the qi as the medicine, the heart as the fire, and the kidneys as water. there is also the moon lying in the lake as the stove, and the jade stove.”
– taken from the document “Golden elixir, question and answers.”