Based on a cluster of Great Peace (taiping 太平) and Weft (wei 緯) materials dealing with stages in human reproduction (impregnation, gestation, intrauterine infancy, birth) and the logic governing annual cycles, this study shows how ontological and cosmological representations were translated into religious discourse and practice in early medieval China and, in particular, became woven into visualisation exercises enabling the adept to revert to a prenatal state of primordial perfection.