"The Śūraṅgama Sūtra, Volume V: The Twenty-Five Saints' Methods of Perfect Penetration - Candraprabha Kumāra"

Original text: Moonlight Child then rose from his seat, paid homage at the Buddha’s feet, and addressed the Buddha, saying: "I recall that in the past, countless kalpas ago as numerous as the sands of the Ganges, a Buddha named Water Heaven appeared in the world. He taught all the Bodhisattvas to cultivate the Water Contemplation. Entering samadhi, I contemplated that within this body, the nature of water is unobstructed. Beginning from tears and saliva, thus I exhaustively contemplated all fluids—essential liquids, vital essence, blood, urine, and feces—revolving within the body. The water nature throughout was identical. I perceived that the water within my body and the water in the lands of the Floating Banner King outside the world, as well as in all fragrant seas of incense, were entirely equal, without any distinction. At that time, I initially accomplished this contemplation, perceiving only the water, yet I had not attained the state of no-body."

Explanation: Moonlight Child rose from his seat, paid homage at the Buddha’s feet, and said to the Buddha: "I recall that countless kalpas ago as numerous as the sands of the Ganges, a Buddha named Water Heaven appeared in the world. He taught all the great Bodhisattvas to cultivate the Water Contemplation. Entering samadhi, I observed that within my physical body, the water element was serene, neither gained nor lost. Beginning from tears and saliva, I gradually observed throughout the entire body, inside and out, without the slightest omission, extending to essential liquids, vital essence, blood, urine, and feces. I observed that all water revolving within the body was identical in nature. I saw that the water element within the body was no different from the water realm in the lands of the Floating Banner King suspended outside the world, nor from the water in all fragrant seas of incense within the world—all were entirely the same, without any distinction. At that time, I had just accomplished this contemplation practice, having reached only the stage of perceiving the great water within the body. I had not yet attained the state of emptying the physical body; there still remained bodily awareness and attachment."

Original text: "While I was a bhikshu, meditating in a room, I had a disciple who peered through the window into the chamber. He saw only clear water filling the entire room, with nothing else visible. Being young and ignorant, he took a piece of tile and threw it into the water, causing a splashing sound, then looked around and left. After I emerged from samadhi, I suddenly felt pain in my heart, like Shariputra when harmed by the obstructive ghost. I reflected: 'Now that I have attained the path of Arhatship, having long been free from causes of illness, why do I suddenly feel heart pain today? Could it be that I have regressed?'

"At that time, the child came before me and recounted the above incident. I then instructed him: 'When you next see the water, immediately open the door, enter this water, and remove the tile.' The child obeyed. Later, when I entered samadhi again, he once more saw the water, with the tile clearly visible. He opened the door and removed it. After I emerged from samadhi, my body felt as it originally had. I encountered immeasurable Buddhas, until finally meeting the Tathagata Sovereign King of Unobstructed Penetration of Mountains and Seas, at which point I attained the state of forgetting the body. My nature merged with the emptiness of the fragrant seas of incense throughout the ten directions, becoming non-dual and indistinguishable. Now, in the presence of the Tathagata, I have received the name 'Child of Truth' and participate in the assembly of Bodhisattvas. The Buddha inquires about perfect penetration. Through the single flavor of the water nature's unobstructed flow, I attained the patience of the non-arising of dharmas and perfected Bodhi. This is foremost."

Explanation: "At that time, I was a bhikshu, sitting in meditation in a meditation chamber. A disciple looked into the room through the window and could only see the chamber filled with clear water; nothing else was visible. As he was still a child, unfamiliar with the states of meditation, he took a piece of tile and threw it into the water in the room, causing a splashing sound. He glanced around, saw no one, and left. After I emerged from samadhi, I suddenly felt pain in my heart, just as Shariputra once did when harmed by a malevolent spirit. I pondered silently: 'Now that I have attained the fruition of Arhatship, my karmic obstacles are eliminated, and I have long been free from causes of illness. Why do I suddenly feel heart pain now? Could it be that my Arhatship has regressed?'

"Then the child came before me and told me about the incident of throwing the tile. I instructed him, saying: 'The next time you see the water, open the door, enter the room, go into the water, and remove that tile.' The child agreed. Later, when I entered samadhi again, the child once more saw the great water in the room, with the tile still in its original place. Thus, the child opened the door and removed the tile. After I emerged from samadhi, I felt my body lightened, with the same sensation as before.

"Later, I encountered immeasurable Buddhas, until I met the Tathagata Sovereign King of Unobstructed Penetration of Mountains and Seas, at which point I forgot the physical body and emptied it. I realized that the nature of this body and all the fragrant seas of incense throughout the ten directions merged with true emptiness, becoming non-dual and indistinguishable. Now, in your presence, World-Honored One, I have received the name 'Child of Truth' and participate in the assembly of Bodhisattvas. The Buddha asks about the method of perfect penetration. It was through contemplating the single-flavored, unobstructed flow of the water nature that I attained the patience of the non-arising of dharmas and perfected the great path of Bodhi. This is the foremost method of my practice."