瑜伽師地論略纂 8.114

8.114

論息因緣中云「一、牽引業」，即先世業。二、「齊處孔穴，或上身分所有孔穴」者，謂齊中有小孔穴，或上身分有口鼻等孔穴。

When discussing the causes and conditions of the breath, the treatise says: "First, pulling karma"—that is, karma from previous lives. "Second, the aperture in the region of the navel, or any aperture in the upper part of the body"—this means there is a small aperture in the navel, or there are apertures such as the mouth and nose in the upper part of the body.