《仪礼·士丧礼》
丧主及众主人从西阶上堂，绕过尸体之足到东边，朝西而袒露左臂。
主人及亲者升自西阶，出于足，西面袒。
The chief mourner and other masters ascend the hall from the western steps, go around the foot of the body to the east side, face west, and uncover their left arms.