This article analyzes the primary terms for purity in Biblical Hebrew, Ugaritic, Sumerian, Akkadian and Hittite. Building on insights from cognitive linguistics and embodiment theory, this study develops the premise that semantic structure – even of seemingly abstract concepts– is grounded in real-world bodily experience. An examination of purity terms reveals that all of them can be related to a concrete sense pertaining to radiance (brilliance, brightness, shininess). The article traces the semantic development of purity terms in distinct experiential contexts and shows how semantic analysis can elucidate the inner logic of fundamental religious concepts.