Abstract The introduction to the ninth-century commentary on the Psalms by Išo‘dad of Merv contains a chapter on historical versus allegorical explanation. The first half of this chapter is about Origen and the Greek origin of allegorical explanation. The second half shows the inadequacy of allegorical explanation on the basis of Paul’s interpretation of the rock in the desert as Christ (1 Cor. 10:4). This article contains a Dutch translation and an analysis in which the possible sources of Išo‘dad’s text are discussed with special attention to the work of Theodore of Mopsuestia.