盐是饮食中不可缺少的调味品，人体若缺盐，健康就会受到影响，出现种种疾病。盐还有防腐、杀菌、解毒、消炎、除污等多种功用，它既是“百药之王”，又是工业之母，确是值得珍视的东西。在许多民族的习俗汇总，盐被当作敬客的高贵礼品。 The Salt of the Earth源自《圣经》，《新约马太福音》记载耶稣对门徒说： “You are the salt of the earth. But if the salt loses its saltiness, how can it be made salty again? It is no longer good for anything.“ Matthew 5:13在这里，salt表示flavor；of the earth即of the world。这句话在后世不断引用变成了一个典故性成语，引申为the most valuable members of sociey；the finest type of humanity；a person or a group of people having the best character 之意。