A scholar nearby asked Dong Yu to give a lecture, but he refused to teach. He only said to others, "Read it a hundred times and you will understand what it means." The consultant said, "(You have a point), but I just don't have time." Dong Yu said: "It should take more than three minutes." . Someone asked what "Sanyu" was. Dong Yu said: "Three leisure times are three kinds of free time. In winter, there is not much farm work. This is the free time of the year; It is not convenient to work in the fields at night, which is a free time of the day; On rainy days, going out to work is not good, and it is also a kind of leisure. "