Listen to this articleyǐnshuǐ-sīyuán 饮水思源
When Drinking Water, One Must Not Forget Its Source.
喝水的时候，要想到水是从哪里来的。南北朝时，庾信（513—581）被迫在北朝客居二十多年，他常常思念故土，写文章说自己喝到河里的水就想到水的源头，以此抒发对于南朝的情怀。后世将原文约为“饮流怀源”或“饮水思源”，比喻不忘本、知感恩。这种纯良的品格，历来为人称道。
When drinking water, one should not forget its source. During the Southern and Northern Dynasties, Yu Xin (513-581) was forced to leave home and stay away from his home state for more than 20 years. Often homesick, he wrote in one of his essays that he always thought of the source of the water whenever he drank form the river, expressing his longing for his hometown in the Southern Dynasties. Eventually this became an idiom: when drinking water one should think of its source, implying that one should never forget his origin and always be grateful. This virtue has always been highly praised.
引例 Citation：
◎落其实者思其树，饮其流者怀其源。（庾信《徵调曲》之六）
（吃到树上结的果实，便想到了结果实的树；喝到河中的水，便想到了河水的源头。）
When eating fruits thinks of the fruit trees; when drinking water thinks of the source of the river. (Yu Xin: The Tune of Zhi)
