Some texts focus on a single topic such as purity/impurity. The texts called Tohorot (Purities) A–C13 deal with people who have gonorrhea, women who are menstruating, men with emissions of semen, unclean vessels, and rules about purity and impurity in connection with the red cow ritual (see Numbers 19). Another set of texts, labeled officially as Ordinances,14 includes rules about produce for the poor, bringing the half-shekel tax once in a lifetime, not annually (as the Pharisees argued),