Looking at the forest you are aware that the trees are providing oxygen for you, and then you see yourself as the forest, as the trees, because without them you can't breathe. You see that the trees and the forest are part of your body. And in big cities you always have a central park. The central park in the city is our lungs, the collective lungs of everyone, of every citizen, otherwise we wouldn't have enough oxygen to breathe. We see it's very crucial that we have a park. That park is our lungs outside of this body.
I know there is a heart inside, and if my heart inside doesn't function, I will die right away. Therefore, I try to do everything I can to protect and to preserve my heart. But when I look at the red sun, and breathe in and out, I see that the sun is another heart of mine. If the sun stops operating I will die right away. That is why I consider the sun as my heart. When you practice like this, you see yourself not limited by the skin of your body. You see that the environment is you. . . . Taking good care of the environment is taking care of yourself.
— Thich Nhat Hanh, Buddha Mind, Buddha Body