The enigmatic description of the columna nubis in lines 71b–92 of the Old English Exodus juxtaposes images of substances that shield God's people from their hostile environment; understanding the relations among these protective coverings requires cultural and literary knowledge not explicitly articulated in Exodus. Metaphors and typologies developed in Arator's sixth-century Historia apostolica and subsequently conventionalized in Bede's eighth-century Expositio actuum Apostolorum, texts used in the Anglo-Saxon monastic curriculum, provide an interpretative framework for the complicated accretion of images in Exodus. Using insights about metaphorical processing from cognitive science, this article argues that the Exodus-poet crafted a sophisticated tripartite conceit to generate a pastoral relationship with his audience, first by adapting metaphoric mappings from Arator and Bede and then by extending their domains with culturally specific entailments about how ships and tents functioned as protective covers in Anglo-Saxon material culture.