"Mao Yan is low and small, and the brook is covered with green grass." People praise the grass because it symbolizes spring and hope. Green grass is lush and intoxicating. Just after the severe winter, people feel the information and hope of spring when they see clumps of green grass coming out of the ground. When people just come out of the hot desert and see a few grasses on the roadside, it is like seeing life and hope, they will forget their thirst.