precept (n.)

"commandment or direction given as a rule of action," especially "an injunction as to moral conduct," late 14c., from Old French percept, percet (12c.) and directly from Latin praeceptum "maxim, rule of conduct, order," noun use of neuter past participle of praecipere "give rules to, order, advise," literally "take beforehand," from prae "before" (see pre-) + capere (past participle captus) "to take," from PIE root *kap- "to grasp." For change of vowel, see biennial. Related: Preceptive; preceptory.