In his memorial On Valuing Grain (论贵粟疏), the Han statesman Chao Cuo described a farming family of five. They plow, weed, harvest and serve in labor duty all year. They still suffer flood and drought, “harsh government and heavy taxes, levies at no fixed time, orders given in the morning and changed in the evening.”
From this line comes the idiom 朝令夕改. Dictionaries define it as government orders or methods that keep changing.