【成语来源】 

塞翁失马

Near China's northern borders lived a man called Sai Weng. He raised a lot of horses.
战国时期,靠近北部边城,住着一个姓塞老人, 他养了许多马。

One day, he lost one of his horses. Everyone commiserated with him.
一天,他的一匹走失了,人们听说这件事,跑来安慰他。

"Perhaps this will soon turn out to be a blessing," said Sai Weng.
塞翁说:“没准会带来什么福气呢。”

After a few months, his horse came back, leading a fine horse from the north.
过了几个月,丢失的马不仅自己回了家,还带回一匹匈奴的骏马。

Everyone congratulated him.
所有人都来祝贺塞翁。

"Perhaps this may turn out to be a cause of misfortune," said Sai Weng.
塞翁反而说:“这或许会带来不幸呢。”

Since he was well-off and kept good horses, his son became fond of riding and eventually broke his leg for falling from a horse.
因为塞翁很富有,并且养马养得很好,所以他的儿子也十分喜爱骑马。但没想到有一次骑马时,他的儿子从马上掉了下来,摔断了腿。

Everyone commiserated with him. "Perhaps this will soon turn out to be a blessing," said his father.
人们于是又去安慰塞翁。但塞翁却说:“也许这次又会带来好运呢。”

One year later, the northern tribes started a big invasion of the border regions.
一年以后,匈奴入侵边境。

This man's son did not join in the fighting because he was crippled and so he survived.
但是塞翁的儿子因为腿断了便没有被征入当兵队伍之中,而其他很多当兵的青年都战死在了沙场,塞翁的儿子因此保住了性命。

【文化链接】 

成语“塞翁失马”如果用于英文表达,可以使用短语“blessing or bane ”,“blessing”的意思是“好运”,“bane”的意思则是“厄运,祸事”,所以放在一起就可以表达“塞翁失马”的意思。

但是,英文表达“blessing or bane ”常会用来单纯的表示“是祸是福”的意思,比如:

Technology, a blessing or a bane?
高科技,是祸是福?