通商惠工

Explanation: Trade: to facilitate the exchange of goods around; benefits: to give people benefits. Smooth flow of trade, to the industrial and commercial benefit. 　　Source: "Min Zuo public two years' service training of agricultural materials, and trade benefits workers. " 　　Examples: After the war to stop, I will state jiggle thin Fu, official Ching Ming, Xing school, award Nongsang, ~. (Yao Xueyin "Rereading" The second volume Chapter 36)