《黄帝内经·素问·腹中论》
若人迎之脉，一倍于寸口脉，是病在少阳；二倍于寸口，是病在太阳；三倍于寸口，是病在阳明，从阳明传入于阴经。
以三阳之动也，人迎一盛少阳，二盛太阳，三盛阳明，入阴也。
If the Renying pulse is one times that of the Cun Kou pulse, the disease is in Shao Yang; if it is two times that of the Cun Kou pulse, the disease is in Tai Yang; if it is three times that of the Cun Kou pulse, the disease is in Yangming, and it spreads from Yangming to Yinjing.