Samu (作務) is participation in the physical work needed to maintain the Zen monastery.^[1][2] According to tradition, it was emphasized by Baizhang Huaihai, who is credited with establishing an early set of rules for Chan (Chinese Zen) monastic discipline, the Pure Rules of Baizhang.^[3] As the Zen monks farmed, it helped them to survive the Great Anti-Buddhist Persecution more than other sects which relied more on donations. These rules are still used today in many Zen monasteries. From this text comes the well-known saying "A day without work is a day without food" (一日不做一日不食 "One day not work, one day not eat").^[4]