This chapter analyses some significant aspects of Heidegger’s elaboration of the idea of the “binding character” or the “bindingness” (Verbindlichkeit) of what has a claim to truth, in the context of his aletheiological reformulation of the notions of freedom and truth. The focus of the essay shall be on Heidegger’s lecture course on The Basic Concepts of Metaphysics (1929/1930) and his essay on The Essence of Ground (1929). After explaining in general terms the systematic importance that Heidegger assigns to the problem of bindingness, the paper examines Heidegger’s understanding of the connection between freedom and bindingness, as it is present in the theoretical-constative access to the world and to beings, both at the ontic and at the ontological level.