《北史·本记·卷二》
二月十五日，下诏说：由于连年多次出征，西北多事，运输服役，百姓辛劳，命令各郡县将百姓按照贫富分为三等级，富裕户照常交纳租税；中等户减免二年租赋；下等贫困户免交三年租赋。
二月戊寅，诏以频年屡征，有事西北，运输之役，百姓勤劳，令郡县括贫富以为三级，富者租赋如常，中者复二年，下穷者复三年。
On the fifteenth day of the second month, the Emperor issued an edict stating that many expeditions had been undertaken in recent years, and that because of the many incidents of maladministration in the northwest and the hardships suffered by the people in rendering transportation and other services, the people of all the commanderies and counties were to be divided into three classes according to wealth: the wealthy were to pay taxes as before; those in the middle income bracket were to be exempt from taxes for two years; and those at the lower income level were to be exempt from taxes for three years.