英语翻译《诗经•小雅•吉日》里有：“吉日庚午,即差我马”八个字,意思是庚午吉日时辰好,是跃马出猎的好日子,这是将午与马相对应的例子.这是最早关于十二生肖的记载.至东汉时,王充《论衡•物势》一书中记载与现今流行的十二生肖完全相同.12生肖本是用于纪年的一套符号,是古代天文历法的一部分,后来成为了普遍被人们认同的生肖历法：子鼠、丑牛、寅虎、卯兔、辰龙、巳蛇、午马、未羊、申猴、酉鸡、戌狗、亥猪.十二生肖两两相对,六道轮回,体现了祖先对我们中国人全部的期望及要求 我们的祖先期望我们要圆融,不能偏颇,要求我们懂得到对应面的切入.

这个的确太难了,
《shijin,xiaoya,jiri》:"ji ri gen wu,ji cha wo ma",This meaning It is a good time to go hunting by rid on good moment at lucky day in year of the Horse,this is the example of matching horse with wu.This is the earliest record about 12 Animals.《lunheng,wushi》recorded the same things by Eastern Han Dynasty.
12 animals is a sign for calendar,and is a part of astronomy calendar in ancientry.they have been accepted by people:zi Rat ,chou Ox,yin tiger,mao rabbit,chen dragon,si snake,wu horse,mo Goat,shen monkey,you Rooster,xu dog,hai pig.12 animals relative to each other,and six tunnel return,represents the hope and requirment which ancient want whole Chinese to do.also our ancient hope us to achieve perfection ,without partial,and require us to understand breakthroughing from corresponding point.