Once there was a farmer whose horse ran away. His neighbor came over to tell him he felt sorry for him, only to be told in return: "Who knows what is good or bad?" It was true. The next day the horse returned, bringing with it eleven wild horses it had met during its adventurous escape. The neighbor came over again, this time to congratulate the farmer on his good fortune. Only to be told once again "Who knows what is good or bad? True this time too; the next day the farmer's son tried to tame one of the wild horses and fell off, breaking his leg. His neighbor came back again one more time to express how bad he felt But for the third time all the farmer had to say was: "Who knows what is good or bad?" And once again the farmer was correct, for this time, the king of that land had started a war and the following day soldiers came by to draft young men into the army, but because of his injury the son was not taken.

The Story is from a book titled Huainanzi(淮南子), which was written in classical chinese(文言).

Classical chinese is the older written form of Chinese, it is different from modern chinese languages, including Mandarin.

below is the story in classical chinese, the text's taken from wikisource:

夫禍福之轉而相生，其變難見也。近塞上之人有善術者，馬無故亡而入胡，人皆弔之。其父曰：「此何遽不為福乎！」居數月，其馬將胡駿馬而歸，人皆賀之。其父曰：「此何遽不能為禍乎！」家富良馬，其子好騎，墮而折其髀，人皆弔之。其父曰：「此何遽不為福乎！」居一年，胡人大入塞，丁壯者引弦而戰，近塞之人，死者十九，此獨以跛之故，父子相保。故福之為禍，禍之為福，化不可極，深不可測也。