“乘”作“四”解,在上古典籍中不乏其例。《孟子·离娄下》:“抽矢,扣轮,去其金,发乘矢而后反。”赵岐注:“乘,四也。”《太玄·迎》:“次五,黄乘否贞。”范望注:“乘,四也。”《仪礼·聘礼》:“乘皮设。”郑玄注:“物四曰乘。”《左传·昭公二十九年》:“帝赐之乘龙,河汉各二。”杜预注:“合为四。”孔颖达疏引服虔曰:“四头为乘。”《仪礼·乡射礼》:“取弓于阶西,兼挟乘矢。”郑玄注:“乘矢,四矢也。”贾公彦疏:“凡物四皆曰乘也。”《说文·马部》“驷”字段玉裁注:“凡物 ”Multiplication “ for ”four “ solution, there is no shortage of examples in ancient classics. ”Mencius from the Lou“: ”pumping vector, buckle round, go to its gold, hair by vector and then counter.“ ”Zhao Qi Note: “ multiplication, four also ”“ too mysterious welcome ”:“ Fifth, the yellow by the zhen. ”Fan Wang Note: “ multiplication, four also. ”“ Ritual dowry: ”by leather set. “ Zheng Xuan Note: ” “Zuo Zhao Gong twenty-nine years”: “Emperor gave the dragon, the two Han.” “Du pre-note: ” combined into four. “” Kong Yingda dredge convincing said: “four for the ride . ”“ Rituals and Township Ritual ”:“ take the bow in the west, and take the vector. ”“ Zheng Xuan Note: ”vector, four vector also. “ Jia Gongyan Shu: ” Jieyue by also. “” Said the text of the horse “” 驷 “Jade field Note: ” Everything