淘沙得金

Explanation: Water method of choice to obtain gold from the sand. Analogy to remove impurities, extract the essence. Also compared the effectiveness of large and less effort. 　　Source: "Guan Yin Zi," In my six or seven for me, such as gold dust, but not if the gold ore. Breaking the gold mine, the gold Panning, Jan gray life, do not get payment also. "