一切經音義 1.18

1.18

毫氂（上胡高反下力馳反案九章算經云凡度之法初起於忽十忽為絲十絲為毫十毫為氂說文毫氂二字竝從毛毫從豪省氂從斄省皆形聲字也今作豪斄非本字假借用也）。

Hairbreadths (毫氂: The upper character has the fanqie hu-gao [háo]; the lower has the fanqie li-chi [lí]. According to the Nine Chapters on the Mathematical Art: 'In the method of measurement, it begins with the hu; ten hu make a si; ten si make a hao; ten hao make a li.' The Shuowen states: 'The two characters hao and li both derive from fur (毛); hao derives from an abbreviation of hao (豪), and li derives from an abbreviation of li (斄); both are phono-semantic compound characters.' The modern writing as 豪斄 is not the original characters, but borrowed use).