What is the earliest reference to either the term shochet or to laws of ritual slaughter? In other words, what is the farthest back in time we can trace the laws of ritual slaughter? I'm looking for specific, stated references (i.e., "So and so can not serve as a shochet because…" or "The knife must made sharp. Any nick or imperfection …") not textual hints. And this is not a quiz – I don't know the answer myself. Readers?