Wei Collection, Lower Volume Radical: Plow (lěi) Kangxi strokes: 11 Page 963, Entry 07 Pronounced si (rising tone) Explaining the characters (Shuowen): Refers to a cha (a type of agricultural tool). Originally written in a variant form, now written as si. Comprehensive dictionary (Yupian): Refers to the wooden part at the front of a lei (an ancient agricultural tool). Broad rhymes (Guangyun): Lei-si (ancient agricultural tools). The Record of Genealogies (Shiben) states: Chui (an ancient craftsman) invented the si. The Examination of Ancient History (Gushikao) states: Shennong invented the si. Book of Changes (Yijing), Appended Statements (Xici): Cutting and shaving wood to make a si. Book of Odes (Shijing), Lesser Odes (Xiaoya): Using my sharp si, I began to plow the southern fields. Book of Rites (Liji), Monthly Ordinances (Yueling): In the final month of winter, order the farmers to plan for the upcoming planting season and to repair the lei and the si. Commentary: The si is the metal part of the lei. It is five inches wide. Rites of Zhou (Zhouli), Winter Officials, Artificer's Record (Kaogongji), The Craftsman: The si is five inches wide; two si placed side by side is called an ou. Sub-commentary: The si refers to the metal blade at the head of the lei; the metal blade is five inches wide. Explanation of Names (Shiming): Si means to resemble; it cuts objects like teeth. Explaining the characters (Shuowen): Sometimes also written in a variant form (li). Collected Rhymes (Jiyun): Sometimes also written in a variant form, and also written in a variant form (tai). Correction: In the Book of Changes (Yijing), Appended Statements (Xici), the text has been carefully corrected from duanmu to zhuomu (cutting wood).