《梦溪笔谈·官政一》
我在三司任职时，曾查到过所谓 三悦 的旧档案， 三悦 实际指的是下列三事：博籴是一悦，便籴是一悦，直便又是一悦。所谓博籴，是说最靠近敌国的第一线边境地区的粮草，每年的输入必定希望能够满足通常应需的数额，所以每年自中央三司下达计划数额给有关仓储机构，都先封存点检现钱、紧便钱和紧茶钞，然后召商人入中。所谓便籴，是说第二线边境地区的粮草，商人先纳粮草入中，再到京师结算请领慢便钱、慢茶钞及杂货。所谓直便，是说商人就便在沿边入纳现钱，然后到京师请领钞引及货物等。此种 三悦 的措施，是在先保证博籴的数量充足之后，才允许便籴及直便。
然后召人入中。 便籴 者，次边粮草，商人先入中粮草，乃诣京师算请慢便钱、慢茶钞及杂货。 慢便钱 谓道路货易非便处， 慢茶钞 谓下三山场榷务。 直便 者，商人取便，于缘边入纳见钱，于京师请领。三说，先博籴，数足，然后听便籴及直便。
When I was working for the Three Bureaus, I once found an old record of the so-called "three enjoyments", which actually refers to the following three things: broad-scale purchase is an enjoyment, cheap purchase is an enjoyment, direct purchase is an enjoyment. The so-called broad-scale purchase refers to the grain and fodder from the border regions closest to the enemy. Every year, the input must meet the usual demand. Therefore, the central government applies a quota to the relevant storage institutions every year. First, count and seal the cash, the immediate money and the tea tickets, and then call the merchants to the capital. The so-called cheap purchase refers to the grain and fodder in the second-tier border region. Merchants first hand in grain and fodder to the capital, and then go to the imperial capital to settle and get slow money, slow tea tickets, and sundries. The so-called direct purchase means that merchants can just hand in cash to the border, and then go to the imperial capital to apply for banknotes and goods. This kind of "three enjoyments" measure is to first guarantee the quantity of broad-scale purchase before allowing for cheap purchase and direct purchase.