《宋史·志·卷二》
六甲六颗星，在华盖杠的旁边，主管区分阴阳，调配节气物候，所以在大帝旁边，用来发布政教、传授农时。
六甲六星，在华盖杠旁，主分阴阳，配节候，故在帝旁，所以布政教、授农时也。
The six stars of hexagrams are located around the beam of Huagai (canopy), and they are in charge of distinguishing Yin and Yang and coordinating seasonal climate. Thus, hexagrams are called the teachings of the emperor and the technique of farming passed down by the emperor.