Abstract. My article is about legal interpretation, but not about the question: how to interpret the law. Rather its aim is to make us consider seriously the question: Why is interpretation central to legal practices? After all not all normative practices assign interpretation such a central role. In this regard the law contrasts with morality. The reason for the contrast has to do with the status of sources in the law. There are no “moral sources” while legal sources are central to the law. Legal interpretation is primarily—I will suggest—the interpretation not of the law, but of its sources. To understand why interpretation is central to legal practices requires understanding the role of sources in the law: the reasons for having them, and hence also the ways in which they should be treated. I will show how reflections about these topics connect with some traditional jurisprudential puzzles, such as the relations between law and morality. Are there gaps in the law? Is the law or its interpretation objective or subjective?