数往知来 解释:
◎ 数往知来 shǔwǎng-zhīlái
[deduce what likely to happen in the future by reviewing what has taken place in the past;know the future by thinking of the past] 追溯过去,可以预测未来
-----------------
国语辞典语本《易经.说卦》:「八卦相错,数往者顺,知来者逆。」指根据已过去的事来推测,就可预知未来。明.陆容《菽园杂记.卷一》:「洪武中,朝廷访求通晓历数,数往知来,试无不验者,必封侯,食禄千五百石。」近温故知新