《管子·明法解》
所以，《明法》篇说： 有权衡之称者，不可以欺以轻重。 
故《明法》曰： 有权衡之称者，不可欺以轻重。 
Therefore, the "Understanding Law" chapter says: It is impossible to deceive with weights and measures those who have established weights and balances. 