《礼记·文王世子》
国君的族人朝见国君，如果是在内朝，则面向东，以北为上位；朝臣中如有地位尊贵者，其位置顺序也只按照年龄辈分排列，由庶子负责安排，即令是贵为上卿，其位置也要在父兄之后。
周公践阼。庶子之正于公族者，教之以孝弟、睦友、子爱，明父子之义、长幼之序。
When the royal relatives meet the monarch, if it is in the inner court, they face east, with the north as the upper position; If there is anyone with a high status among the courtiers, the order of their positions is also arranged according to their age and seniority, and Shuozi is responsible for the arrangement, even if he is a high-ranking person, his position should be after his father and brother.