Anastasius was probably the author of the Hexaemeron, a commentary in 12 books about the Genesis creation narrative. (Hexaemeron, sometimes spelled Hexameron, means six-days.) In the Hexaemeron Anastasius argues that Moses on Mount Sinai was inspired by the Holy Spirit to write not only the creation narrative, but also in the same text to prophesize the New Creation through Christ. Thus Adam represents Christ and Eve represents the Church. Anastasius' extensive exegesis of the beginning of Genesis draws upon commentaries written by many Fathers of the Church, including Clement of Alexandria, Origen, Gregory of Nyssa, Gregory of Nazianzus, and Pseudo-Dionysius the Areopagite. One reason for some doubts about Anastasius' authorship is the lack of any surviving manuscript copied before the end of the fifteenth century. The lack of earlier manuscripts, however, could be the result of censorship. The allegorical interpretations of Genesis in the Hexaemeron by Anastasius are in many ways a counterpoint to the more literal Hexaemeron written by Basil the Great.