《礼记·檀弓下》
国君对于大夫的丧事，在大夫将葬的时候，要先到殡宫吊丧。等到柩车出来，要命随从执纬拉车，往前拉三步就停下来。
君于大夫，将葬，吊于宫；及出，命引之，三步则止。
For mourning rites of high officials, when it is time for the high official to be buried by the country lord, the lord should first go to the funeral hall to express his condolences. When the coffin is taken out, he should order his followers to hold the curtain of the chariot, and the chariot moves three steps forward and then stops.