《仪礼·士丧礼》
国君继命公、卿、大夫上堂，立于丧主之西视殓，以东为上。
升公卿大夫，继主人，东上。
The sovereign continues to order the dukes, ministers, and high officials to ascend the hall and stand to the west of the chief mourner to inspect the burial, with east being the higher position.