"Ruiju sandai kaku" (Assorted regulations from Three Reigns) indicates that Daijokanpu (official documents of the Daijokan, the office of the supreme political leader) were issued in 811 to forbid confiscating peasants' newly cultivated land in Mutsu, Dewa provinces.
弘仁2年（811年）には陸奥出羽で百姓の墾田を収公するのを禁じる太政官符が出されたことが『類聚三代格』からわかる。