sutra (n.)youdaoicibaDictYouDict[sutra 词源字典]
in Buddhism, "series of aphorisms" concerning ceremonies, rites, and conduct, 1801, from Sanskrit sutram "rule," literally "string, thread" (as a measure of straightness), from sivyati "sew;" cognate with Latin suere "to sew" (see sew). Applied also to rules of grammar, law, philosophy, etc., along with their commentaries.[sutra etymology, sutra origin, 英语词源]