Niddah (or nidah, nidda, nida; Hebrew:נִדָּה) is a Hebrew term which literally means separation, generally considered to refer to separation from ritual impurity; Ibn Ezra argues that it's related to the term menaddekem, meaning cast you out. The term niddah appears in the biblical description of the red heifer ceremony, in the phrase waters of [niddah]; the septuagint renders this as waters of sprinkling. However, the term niddah is overwhelmingly use… (More on Niddah)