the one and only way的意思|示意

不二法门 Such as “一尘不染(spotless)” , “不二法门(the one and only way)” , “五体投地(to deeply admire)”.

原为佛教用语 ...原为佛教用语, 现比喻独一无二的门径) the only proper course to take; the only correct approach to a subject [success]; the one and only way; the only effective means; the standard practice..