《汉书·志·郊祀志下》
天地以帝王为主导，所以圣王制定祭祀天地的礼仪一定在国都郊外。
天地以王者为主，故圣王制祭天地之礼必于国郊。
Heaven and earth are led by the emperor, so the sage king must establish the ritual of worshipping heaven and earth in the suburbs of the capital.