A long journey tests the strength of a horse; the first half of a couplet suggesting that a person's true character is only revealed over a long period of time. Usually followed by 日久见人心rìjiǔjiànrénxīn.
Lù Yáo Zhī Mǎ Lì
Name of a traditional opera set in the Song Dynasty, depicting the story of the deep friendship between the characters Lu Yao and Ma Li