甘之如荠

Explanation: Water chestnut: beet. Tea has a bitter dish, but compared to the pain and heart, I feel as sweet as shepherd's purse. Refers to things such as happy, after whom, and adversity are sweet. With the "willing, such as water chestnut." 　　Source: "Liu Jin Shu Shen Chuan": "cast sleeve of a robe of the date of the death. Potamogeton minced meat of the kill, Gan, such as water chestnut." Thesaurus:  Willingly Such as water chestnut