"Chang 'an Que settled here in Liu, and there were only many funerals" (Chang Ling in Tang Dynasty) Zhao Mu made "is the arrangement order of ancient ancestral temples. According to "Zhou Li Chun Guan Xiao Yu Love Bo", "Distinguish temples. Zheng Xuan said: "Self-ancestor, father is Zhao, son is Mu." . "
In other words, the ancestors are in the middle of the ancestral hall, and the descendants below are arranged in two columns, Zhao on the left and Mu on the right. The son of the ancestor is Zhao, and the grandson of the ancestor is Mu; The first grandchild's son is Zhao, and the first grandchild's grandson is Mu. In Zhao Mu's arrangement, father and son are always in different columns, and grandparents and grandchildren are always in the same column. In addition, the burial places in the cemetery are also divided into left and right orders based on this.
Du Dongyuan's Xuan Di Ling Du was not built in the North District for two reasons. First of all, Xuan Di grew up among the people. Before he became emperor, he traveled all over the land of Sanfu, especially the Xiadu City between DuDu and Min counties, and he had a good impression on the local area. His parents were buried in the southeast of Chang 'an, so Xuan Di chose to build a mausoleum in Yuanshang, Du Dong. Secondly, yes, grandson, both of them are Zhao's official positions. After Zhao Di acceded to the throne, Liu Xun could not pre-build a mausoleum on the original site of Xianyang, so he had to build a Ling Du on the original site of Du Dongyuan in the southeast of Chang 'an.