《黄帝内经·素问·逆调论》
阳明是胃脉，胃是六腑之海，胃气亦以下行为顺，若阳明经脉之气逆，胃气便不得循常道而下行，所以不能平卧。
阳明者，胃脉也，胃者，六府之海，其气亦下行，阳明逆，不得从其道，故不得卧也。
Yangming is the stomach meridian, and the stomach is the sea of the six fu-organs. The stomach qi also follows the downward behavior to be smooth. If the qi of the Yangming meridian is reversed, the stomach qi cannot follow the usual path and go down, so it cannot lie flat.