一切經音義 22.261

22.261

國城財貝（貝北賴反說文曰貝謂今海蟲也古者貨貝而寶龜也謂海虫有甲作錦文者也今西域用貝為錢故云財貝也）。

Property and cowries of cities and realms (guo cheng cai bei; bei is pronounced bei [北] + lai [賴] in fanqie. The Shuowen says: 'Bei refers to modern marine creatures. In antiquity, cowries were money and tortoises were treasures.' It refers to shelled marine creatures that display brocade patterns. Today in the Western Regions, cowries are used as currency, hence they are called cai bei).