The nature of water is true emptiness; the nature of emptiness is true water.

In the Śūraṅgama Sūtra, it is said that "the nature of water is true emptiness, and the nature of emptiness is true water." Here, water refers to water that has already been generated from the seed of the water element, including water particles and the water in rivers, lakes, and seas. The substance of this water is composed of water particles; the particles are constituted by the water element. The water element is an inherent seed within the tathāgatagarbha, belonging to the tathāgatagarbha, and its nature is also the nature of the tathāgatagarbha. Therefore, all water constituted by the water element is, in essence, of the nature of the tathāgatagarbha. What is the nature of the tathāgatagarbha? The tathāgatagarbha is emptiness/voidness (śūnyatā)—empty all the way through, without any dharmas; both the emptier and the emptied are completely empty, even emptiness itself is empty, utterly clean, without a single speck of dust. Thus, the nature of any water is true emptiness, and within that emptiness there is also the true water-nature that neither arises nor ceases. Therefore, when the tathāgatagarbha encounters conditions, it can produce water. If there were no unborn and unceasing water-nature within the tathāgatagarbha, then no matter what conditions and causes appeared, water could not be produced.

Therefore, as for our thoughts, just keep emptying them, keep emptying away all dharmas. When you have emptied to the very end, with nothing left to empty, you have arrived home—sitting in the home of the tathāgatagarbha, greatly turning the Dharma wheel. Why is it that when everything has been emptied away and nothing remains, one can still turn the Dharma wheel? Because within the emptiness of the tathāgatagarbha there are still the true earth, true water, true fire, true wind, true seeing, and true consciousness—unborn and unceasing, genuinely existent—and when conditions are present, all dharmas can be produced. After attaining buddhahood, the power of vows does not cease, and thus conditions do not cease; together with the unceasing seeds of the seven great elements within the tathāgatagarbha, the Tathāgata is free to turn the great Dharma wheel and deliver all suffering sentient beings.