yesterday is history 的那个名言怎么说的?

Yesterday is history,tomorrow is a mystery,today is God's gift,that's why we call it the present.
昨天已成历史,明天还是神秘之事,今天是上帝的小礼物,这是我们为何叫它present的原因.
present是双关语,一为“礼物”,一为“现时”.
明白了吗?