称兄道弟是我国传统敬辞中极为通用和常见的。子夏尝言:“君子敬而无失,与人恭而有礼。四海之内,皆兄弟也。”清·钱大昕《恒言录》“友朋相称兄弟”条记载:“马良《与诸葛亮书》称亮为‘尊兄’;《蜀记》关羽称徐晃为‘大兄’;《南史》王僧绰谓中书侍郎蔡兴宗曰:‘弟名位应与新建齐’;范蔚宗谓何尚之:‘弟就死之后,犹望君照此心也。’”朋友以兄弟相称在书信中亦相当普遍。《礼记·曲礼》有云:“夫礼者,自卑而尊人。”写信时自称宜谦,称人宜恭。在书信往来中, Brotherhood is a very common and common tradition in our country. Zi Xia taste: “gentleman respectless without respect, and others are courteous and courteous. Within the four seas, are brothers. ” Qing Qian Daxin “Saying” “friends and fraternal comrades ” article records: “Ma Liang” and Zhuge Liang book “said Liang as’ respect for brother ’;’ Shu Kee ’said Xu Huang as’ big brother’; ’history of the South’ Wang Monk Chao said the book assistant minister Cai Xingzong said: ’brother position should be with the new Qi Fan Weizong said He Shangzhi: After his brother died, he would still like to take this as his heart. ”“ Friends are also quite common in letters as brothers. ”Book of Rites Music Man“ there is a cloud: ”Fu ceremony, inferiority and respect people.“ ”When writing claiming Yi Qian, said people should Christine. In correspondence,