"Hindu Law is the law of Smritis" was said by:

In his classic treatise Hindu Law and Usage, John D. Mayne (often spelled "Maine" in Indian legal literature) famously defined Hindu Law as "the law of the Smritis as expounded in the Sanskrit Commentaries and Digests which, as modified and supplemented by custom, is administered by the Courts." This definition highlights that classical Hindu jurisprudence is primarily rooted in the Smritis as interpreted by authoritative commentaries and modified by recognised custom.