Hebrews features seventeen out of the thirty-three uses of διαθήκη in the New Testament, the overwhelming majority of which occur in chapters 8–10. While the term itself often draws attention as a point of exegesis or in reaching one’s conclusions on the meaning of that exegesis, scholars have very different understandings of what διαθήκη means and how the author is employing it conceptually. Options put forward range from limited contracts to testaments all the way to something functioning more like a constitution for a nation. From a different perspective, “covenant” as a concept is often a key feature in systematic and biblical theologies. Some authors even see it as the framework for the history of redemption. Often the term is analyzed without sufficient attention to the meaning in the text itself. After displaying this tension, this paper proposes that this dialogue can be moved forward through the analysis of the argumentation of Hebrews itself. The types of arguments the author uses should shape the way the concepts themselves are received. Analyzing the conceptual framework surrounding διαθήκη and the author’s theological judgements brings clarity to its meaning and use in Hebrews.