“Enlightenment is like the moon reflected on the water. The moon does not get wet, nor is the water broken. Although its light is wide and great, the moon is reflected even in a puddle an inch wide. The whole moon and the entire sky are reflected in dewdrops on the grass, or even in one drop of water.”
— Zen Master Eihei Dōgen

The full moon has great significance in Zen, representing enlightenment. You will find it referred to frequently in Zen texts, particularly those of Zen Master Eihei Dōgen. Is there more we really need to point us to our True Nature, than these few words of Dōgen's?