Hexaemeron (Basil of Caesarea) in the context of Philo of Alexandria

The term Hexaemeron (Greek: Ἡ Ἑξαήμερος Δημιουργία Hē Hexaēmeros Dēmiourgia), literally "six days," is used in one of two senses. In one sense, it refers to the Genesis creation narrative spanning Genesis 1:1–2:3: corresponding to the creation of the light (day 1); the sky (day 2); the earth, seas, and vegetation (day 3); the sun and moon (day 4); animals of the air and sea (day 5); and land animals and humans (day 6). God then rests from his work on the seventh day of creation, the Sabbath.

In a second sense, the Genesis creation narrative inspired a didactic genre of Jewish and Christian literature known as the Hexaemeral literature. Literary treatments in this genre are called Hexaemeron. This literature was dedicated to the composition of commentaries, homilies, and treatises concerned with the exegesis of the biblical creation narrative through ancient and medieval times and with expounding the meaning of the six days as well as the origins of the world. The first Christian example of this genre was the Hexaemeron of Basil of Caesarea, and many other works went on to be written from authors including Augustine of Hippo, Jacob of Serugh, Jacob of Edessa, Bonaventure, and so on. These treatises would become popular and often cover a wide variety of topics, including cosmology, science, theology, theological anthropology, and God's nature. The word can also sometimes denote more passing or incidental descriptions or discussions on the six days of creation, such as in the brief occurrences that appear in Quranic cosmology.