Chen Collection, Middle Volume. Radical: Tree (mù). Kangxi strokes: 13. Page 538, Entry 15. Pronounced pian. According to the Shuo Wen Jiezi (Dictionary of Explanations of Characters), it is a square piece of timber. In the Zuo Zhuan (Commentary of Zuo), it is written as a plank support. Du Yu says: It is a tray for placing inside a coffin. In the Zuo Zhuan (Commentary of Zuo), 25th year of Duke Zhao: A plank support is used to support the coffin. Also, in the Ode on the Jingfu Hall by He Yan: There are restricted short rafters, carved and divided with wings spread. Li Shan annotates: Restricted short rafters are short rafters. Pronounced bian. A type of tree. In the Classic of Mountains and Seas (Shanhaijing): On Du Mountain there is a tree, named the Heaven Plank, with a square stem and leaves shaped like mallow; those who consume it will not suffer from illness.