塞翁失马（塞翁失馬）　

◎ 塞翁失马 sàiwēng-shīmǎ

[a blessing in disguise;a loss may turn out to be a gain;the old man‘s loss of horse may be a fortune in disguise] 边塞一老翁丢了一匹马,人家来安慰他,他却说:“怎么知道这不是福呢?”过了些日子,这匹马竟然带着一匹好马回来了(见于《淮南子·人间》)。比喻暂时受损却可能因此受益,坏事在一定条件下可以变为好事