Wu Collection, Lower Volume Radical: Cave (xué) Kangxi Strokes: 18 Page 869, Entry 01 Pronounced qiao (falling tone) Shuowen Jiezi: A hole or cavity, an empty or vacant space. Book of Rites (Liji): The earth holds the yin cavities in the mountains and rivers. Commentary: This means the earth holds the yin energy, creating holes in the mountains and rivers, which are used to exhale and inhale. Rites of Zhou (Zhouli): The changes of the nine orifices are doubled. Commentary: There are seven yang orifices and two yin orifices. Commentary: The seven yang orifices are located on the head and are visible, hence they are called yang orifices. The two yin orifices are located on the lower part of the body and are not exposed, hence they are called yin orifices. Medicines that are slippery in nature can nourish the orifices. Commentary: All types of slippery substances can clear the passages, just as holes allow for movement, and are therefore used to nourish the channels. Classic of Mountains and Seas (Shanhaijing): The Chest-pierced Kingdom, the people there have a hole through their chests. Textual Research: In the Book of Rites (Liji), the original text stated the earth holds the cavities in the mountains and rivers. Following the original text, the word yin has been added after the earth holds.