One nature perfectly pervades all natures:
One Dharma includes all dharmas.
One moon appears in all waters;
The moons reflected in all waters are one.
Water is water, no matter where it is. Whether a dew drop or an ocean, it is still water. Buddha-nature is in your body and in mine, in a dog, a pig, the grass. Buddha-nature is everywhere the same. Dog shit has the same Buddha-nature as did Sakyamuni Buddha. There is no difference. If you look closely enough, you will see in all things the same thing, and everything. There is no difference between a grain of sand and King Solomon’s treasures.
Of course, if you preached this idea on the street, people would think you were crazy. These verses explain an ultimate principle, not everyday phenomena. If you think it is okay to go to the bathroom and bow to the toilet instead of to the Buddha, think again.
A disciple of Master Hsuan-hua in California heard the master make a similar statement, so at dinnertime he put a piece of shit on the dinner table. Master Hsuan-hua asked, “What are you doing?”
The disciple then reprimanded him: “See, that’s discrimination! You have a discriminating mind!” After that incident, Master Hsuan-hua told him to leave. This particular monk thought highly of himself, and instead of listening to his master’s instructions, he insisted on doing things his own way. He was not interested in learning; he only wanted to challenge the master. In the case of this story, he failed to understand that the principle, or noumenal realm, is different from the phenomenal realm. Master Hsuan-hua explained, “You don’t put shit on the dinner table. Sakyamuni never ate shit. When I say shit and Sakyamuni are the same, I am talking about a realization that comes through practice. I am not talking about the concrete world. In the phenomenal world, phenomena are still phenomena. Sakyamuni is still Sakyamuni, shit is still shit.” An enlightened person understands and acknowledges that the world of phenomena is not the same as the principle.
— The Sword of Wisdom by Master Sheng-Yen (page 162)