Any important rule.

Roget 496: maxim, aphorism; apothegm, apophthegm^†; dictum, saying, adage, saw, proverb; sentence, mot [Fr.], motto, word, byword, moral, phylactery, protasis^†.    axiom, theorem, scholium^†, truism, postulate.    first principles, a priori fact, assumption (supposition) 514.    reflection etc. (idea) 453; conclusion etc. (judgment) 480; golden rule etc. (precept) 697; principle, principia [Lat.]; profession of faith etc. (belief) 484; settled principle, accepted principle, formula.    accepted fact.    received truth, wise maxim, sage maxim, received maxim, admitted maxim, recognized maxim &c.; true saying, common saying, hackneyed saying, trite saying, commonplace saying etc. ... show more

Roget 697: precept, direction, instruction, charge; prescript, prescription; recipe, receipt; golden rule; maxim etc. 496.    rule, canon, law, code, corpus juris [Lat.], lex scripta [Lat.], act, statute, rubric, stage direction, regulation; form, formula, formulary; technicality; canon law; norm.    order etc. (command) 741.    ... show more

A command based on Jesus' words in the Sermon on the Mount.