Tjitze Baarda, ‘If You Do Not Sabbatize the Sabbath ...’: The Sabbath as God or World in Gnostic Understanding (Ev. Thom., Log. 27), in: idem, Essays on the Diatessaron (Contributions to Biblical Exegesis and Theology, 11), Kampen: Kok Pharos, 1994, p. 141-171.