Lectures on the Sūtra of the Collection of the Father and Son (Pitāputrasamāgamanasūtra) (39)

The external fire element comes from nowhere and goes nowhere

The external fire element is jointly sustained by the tathāgatagarbhas of sentient beings who share common karma. The tathāgatagarbha of a single individual cannot sustain the external fire element; it can only sustain the fire element within one's own body. In the past, unlike today, there were no matches or lighters; people used other methods to make fire. They held a convex lens under sunlight to focus the rays and ignite wormwood, dried cow dung, or cattail down. Once ignited, these were used to kindle other things, to make fire for cooking, or to burn other materials.

Once this fire is burning, it may consume grass, trees, mountains, forests, and villages. Originally there was not a single spark, but once this fire arises, it will blaze across mountains and fields. It can burn an entire mountain to nothing; trees however tall, forests however vast, are all destroyed. If the fire spreads further, it can destroy the entire world. Where does this fire come from? Setting aside for the moment that it comes from the tathāgatagarbha, let us first speak of emptiness. If fire came from the sun, then without holding a convex lens in one's hand, no matter how the sun shone, no fire would be produced. If the sun had fire capable of burning forests, it could also roast the bodies of us sentient beings; we would die anytime and anywhere, and no life could exist in the world. Therefore, fire does not come from the sun.

Does fire come from empty space? It does not come from empty space either. If there were fire in empty space, all objects would be burned up, and the world would be left with nothing. Fire does not come from the sun, not from empty space, not from a person's hand, not from the lens, not from the grass—it has no place of coming. Let us first present the Hīnayāna explanation. The fire element comes from nowhere, and when the fire finally goes out, where does it go? It has no destination; it goes nowhere. If it had a destination, then wherever it went, things would burn. The fire element is simply the nature of burning and the nature of heat: it comes from nowhere and goes nowhere; when it comes, no place of coming can be found; when it goes, no destination can be found. In essence, it is all the nature of the tathāgatagarbha, the function of the tathāgatagarbha. Therefore, when all dharmas are traced to their end, they all resolve to that true mind of ours. Apart from this, not a single dharma is real.