Ananda, fire, which has no nature of its own, depends upon various causes and conditions for its existence. Consider a family in the city that has not yet eaten. When they wish to prepare food, they hold up a speculum to the sun, seeking fire.
"Ananda, let us look into your suggestion that the fire comes forth from mixing and uniting. By way of example, you and I and the twelve hundred and fifty Bhikshus unite together to form a community. However, a careful analysis of the community reveals that every member composing it has his own body, birthplace, clan, and name. For instance, Shariputra is a Brahman; Uruvilva is of the Kashyapa clan, and you, Ananda, come from the Gautama family.
"Ananda, suppose fire existed because of mixing and uniting. When the hand holds up the speculum to the sun to seek fire, does the fire come out of the speculum? Does it come out of moxa tinder? Or does it come from the sun?
"Suppose, Ananda, that it came from the sun. Not only would it burn the moxa tinder in your hand, but as it came across the groves of trees, it should burn them up as well.
"Suppose that it came from the speculum. Since it came out from within the speculum to ignite the moxa tinder, why doesn't the speculum melt? Yet your hand that holds it feels no heat; how, then, could the speculum melt?
"Suppose that the fire came from the moxa tinder. Then why is fire generated only when the bright mirror comes into contact with the dazzling light?
"Furthermore, on closer examination you will find the speculum held in hands, the sun high up in the sky, and moxa grown from the ground. Where does the fire come from? How can it travel some distance to reach here?
"The sun and the speculum cannot mix and unite, since they are far apart from each other. Nor can it be that the fire exists spontaneously, without an origin.
"You simply do not know that in the treasury of the Thus Come One, the nature of fire is true emptiness, and the nature of emptiness is true fire. Pure at its origin, it pervades the Dharma realm. It accords with living beings' minds, in response to their capacity to know.
"Ananda, you should know that fire is generated in the place where a speculum is held up to the sunlight, and fire will be generated everywhere if specula are held up to the sunlight throughout the Dharmas realm. Since fire can come forth throughout the whole world, can there be any fixed place to which it is confined?
"It is experienced to whatever extent is dictated by the Law of Karma. Ignorant of this fact, people in the world are so deluded as to assign its origin to causes and conditions or to spontaneity. These mistakes, which arise from the discriminations and reasoning processes of the conscious mind, are nothing but the play of empty words which have no real meaning.