This essay considers the complex structure of Hebrews, focusing on the role of the opening statement of the book. The study finds causation with parallel instances of particularization, the author providing general statements in both the cause (1:1–4) and effect (10:22–25) which are then subsequently unpacked through the rest of each main unit of material. Emphasis is placed on the role of 1:1–4 in the context of the author’s argument regarding God’s eschatological revelation in the Christ-event. This revelation is made ἐν υἱῷ (1:2a), an expression long undervalued by scholars but one that provides the basis for and understanding of the various themes in Hebrews.