八(ba)咫有(you)大或美的意思。八(ba)咫鏡(jing)起(qi)源于(yu)中(zhong)國的水鏡(jing),又稱(cheng)“鑒(jian)”。就是在(zai)一個金(jin)屬盆(pen)中(zhong)放上水,用以照面。后來逐漸發展成銅鏡(jing),背面繪刻有(you)松竹(zhu)梅(mei)、龜鶴等吉祥圖(tu)案。
當(dang)時日本人(ren)視鏡(jing)子(zi)(zi)為神圣物(wu)品,掛于(yu)胸前作為避邪用具。之后鏡(jing)子(zi)(zi)種(zhong)類增多(duo)(duo),其中的(de)(de)八咫鏡(jing)作為天照(zhao)大(da)神的(de)(de)御靈(ling),祭在日本神社之祖伊勢神宮內。鏡(jing)子(zi)(zi)在日本民俗(su)中占有相當(dang)高的(de)(de)地位。日本人(ren)認為鏡(jing)子(zi)(zi)能照(zhao)物(wu)照(zhao)人(ren),本身就(jiu)說(shuo)明它具有神秘性和魔力,所以(yi)有關鏡(jing)子(zi)(zi)的(de)(de)信仰和傳說(shuo)很多(duo)(duo)。說(shuo)它可(ke)引來吉(ji)祥,映(ying)照(zhao)出人(ren)心,可(ke)暴露惡魔的(de)(de)本質,預見生(sheng)死吉(ji)兇。由此,日本至(zhi)今有人(ren)認為鏡(jing)子(zi)(zi)破(po)碎是不祥之兆(zhao),不能跨越(yue)鏡(jing)子(zi)(zi),非吉(ji)慶場合要把鏡(jing)子(zi)(zi)遮蓋起來等(deng)等(deng)。
日(ri)本傳(chuan)說中有“三神器”,分(fen)別(bie)是草薙劍、八尺瓊勾玉、八咫鏡。
八咫鏡(jing)又叫真(zhen)(zhen)經津之(zhi)鏡(jing),日(ri)本傳說(shuo)三神器(qi)之(zhi)一,現在(zai)(zai)(zai)(zai)(zai)(zai)(zai)供奉在(zai)(zai)(zai)(zai)(zai)(zai)(zai)伊勢神宮。由于天(tian)(tian)(tian)(tian)照(zhao)(zhao)(zhao)(zhao)大(da)神的(de)(de)(de)弟弟須佐之(zhi)男大(da)鬧(nao)高(gao)(gao)天(tian)(tian)(tian)(tian)原(yuan)(yuan)(yuan)闖了(le)(le)禍,天(tian)(tian)(tian)(tian)照(zhao)(zhao)(zhao)(zhao)大(da)神十分惶恐,躲在(zai)(zai)(zai)(zai)(zai)(zai)(zai)天(tian)(tian)(tian)(tian)之(zhi)巖戶不(bu)(bu)出來了(le)(le)。她(ta)(ta)可是(shi)高(gao)(gao)天(tian)(tian)(tian)(tian)原(yuan)(yuan)(yuan)的(de)(de)(de)老(lao)大(da),沒(mei)(mei)她(ta)(ta),高(gao)(gao)天(tian)(tian)(tian)(tian)原(yuan)(yuan)(yuan)和(he)葦原(yuan)(yuan)(yuan)中(zhong)國(guo)都(dou)(dou)變得一片漆黑,于是(shi)有(you)人出主意,用天(tian)(tian)(tian)(tian)安(an)河上(shang)的(de)(de)(de)天(tian)(tian)(tian)(tian)堅石和(he)天(tian)(tian)(tian)(tian)金(jin)山的(de)(de)(de)鐵造出八咫鏡(jing),掛(gua)(gua)在(zai)(zai)(zai)(zai)(zai)(zai)(zai)真(zhen)(zhen)賢樹上(shang),八百萬眾神一起在(zai)(zai)(zai)(zai)(zai)(zai)(zai)外面(mian)唱歌跳舞(wu),弄得高(gao)(gao)天(tian)(tian)(tian)(tian)原(yuan)(yuan)(yuan)雞犬不(bu)(bu)寧。天(tian)(tian)(tian)(tian)照(zhao)(zhao)(zhao)(zhao)很奇怪,就在(zai)(zai)(zai)(zai)(zai)(zai)(zai)里面(mian)問:“我隱居在(zai)(zai)(zai)(zai)(zai)(zai)(zai)這(zhe)(zhe)里,高(gao)(gao)天(tian)(tian)(tian)(tian)原(yuan)(yuan)(yuan)黑暗(an)了(le)(le),葦原(yuan)(yuan)(yuan)中(zhong)國(guo)也(ye)都(dou)(dou)黑暗(an)了(le)(le),為(wei)什(shen)么(me)天(tian)(tian)(tian)(tian)宇受賣(mai)命(ming)還(huan)在(zai)(zai)(zai)(zai)(zai)(zai)(zai)歌舞(wu),而八百萬眾神也(ye)都(dou)(dou)在(zai)(zai)(zai)(zai)(zai)(zai)(zai)高(gao)(gao)聲歡(huan)笑呢?”天(tian)(tian)(tian)(tian)宇受賣(mai)命(ming)回答說(shuo):“有(you)比(bi)你更尊貴(gui)的(de)(de)(de)神來了(le)(le),所以我們在(zai)(zai)(zai)(zai)(zai)(zai)(zai)歡(huan)樂歌舞(wu)。”說(shuo)話之(zhi)間,天(tian)(tian)(tian)(tian)兒屋命(ming)和(he)天(tian)(tian)(tian)(tian)布刀玉命(ming)舉起掛(gua)(gua)在(zai)(zai)(zai)(zai)(zai)(zai)(zai)真(zhen)(zhen)賢樹枝(zhi)上(shang)的(de)(de)(de)八咫鏡(jing),讓天(tian)(tian)(tian)(tian)照(zhao)(zhao)(zhao)(zhao)大(da)御神照(zhao)(zhao)(zhao)(zhao)著鏡(jing)子(zi)看。天(tian)(tian)(tian)(tian)照(zhao)(zhao)(zhao)(zhao)大(da)御神說(shuo):“這(zhe)(zhe)家(jia)伙是(shi)誰,難道比(bi)我還(huan)尊貴(gui)嗎?”天(tian)(tian)(tian)(tian)照(zhao)(zhao)(zhao)(zhao)光顧著看鏡(jing)子(zi),沒(mei)(mei)留神從門里出來了(le)(le),這(zhe)(zhe)時隱藏在(zai)(zai)(zai)(zai)(zai)(zai)(zai)門旁的(de)(de)(de)天(tian)(tian)(tian)(tian)手力男神,便抓住她(ta)(ta)的(de)(de)(de)手,把(ba)她(ta)(ta)拉出來。天(tian)(tian)(tian)(tian)布刀玉命(ming)趕忙(mang)把(ba)注連(lian)繩掛(gua)(gua)在(zai)(zai)(zai)(zai)(zai)(zai)(zai)她(ta)(ta)的(de)(de)(de)后面(mian),說(shuo)道:“不(bu)(bu)許再回到里邊去(qu)了(le)(le)!”天(tian)(tian)(tian)(tian)照(zhao)(zhao)(zhao)(zhao)大(da)御神一出來,高(gao)(gao)天(tian)(tian)(tian)(tian)原(yuan)(yuan)(yuan)和(he)葦原(yuan)(yuan)(yuan)中(zhong)國(guo)立即天(tian)(tian)(tian)(tian)光大(da)亮。后來,天(tian)(tian)(tian)(tian)照(zhao)(zhao)(zhao)(zhao)把(ba)這(zhe)(zhe)面(mian)鏡(jing)子(zi)也(ye)作(zuo)為(wei)神器(qi)給了(le)(le)天(tian)(tian)(tian)(tian)孫,并且說(shuo):“要永(yong)遠把(ba)這(zhe)(zhe)面(mian)鏡(jing)子(zi)當作(zuo)我的(de)(de)(de)化身來莊嚴的(de)(de)(de)祭祀”。