It's dark outside

As soon as Te Shan crossed the threshold he said, "Long have I heard of Lung T'an (Dragon Pond), but now that I've arrived here, there's no pond to see and no dragon appears." Master Lung T'an came out from behind a screen and said, "You have really arrived at Lung T'an." Te Shan bowed and withdrew.

During the night, Te Shan entered Lung T'an's room and stood in attendance till late at night. Lung T'an said, "Why don't you go?" Te Shan bade farewell, lifted up the curtain, and went out; he saw that it was dark outside, so he turned around and said, "It's dark outside." Lung T'an lit a paper lantern and handed it to Te Shan; as soon as Te Shan took it, Lung T'an blew it out. Te Shan was vastly and greatly enlightened.

  1. ​In a state of reverberation​