《旧五代史·后唐·列传十》
到商汤革命时，重新制定田制，每私田十亩，种公田一亩，水田旱地相同，也是什一税的意思。
及商革夏命，重立田制，每私田十亩，种公田一亩，水旱同之，亦什一之义也。
When Shangtang revolutionized, a new land system was formulated, every private field of ten acres, and one acre of public field, the water field and dry land are the same, which also means one-tenth of the tax.