Laws of ritual purity

The laws of ritual purity, however, do not concern forbidden acts. They concern human conditions or states which occur despite human volition. Sometimes they are the consequence of actions which in themselves are meritorious. To be in a state of ritual impurity is never a sin; but the suffer of ritual impurity has to be careful not contact sacred areas or objects until he has rid himself of his impurity by the prescribed method of purification.

For example, an Israelite attends a family funeral. This in itself is a meritorious act, showing family feeling and respect for the dead. but proximity to a corpse causes a seven-day ritual impurity, which must be removed if the Israelite has occasion to enter the Temple...Or a husband and wife have sexual intercourse. But this act, though meritorious, since it fulfils the commandment to be fruitful and multiply and 'makes the loved companions to rejoice', causes one-day ritual impurity to both husband and wife, which they must remove before their next visit to the Temple. Other impurities are incurred by natural processes: menstruation and childbirth; others by misfortunes: leprosy and abnormal genital discharges. not one of these conditions is sinful. Many mistakes...would be avoided if this were better understood.

What the dietary laws and the ritual purity laws have in common is that they form part of the priestly code laid down in the Torah for the Israelites as a priest-nation. It is significant that none of these laws is included in the Ten Commandments, or in any of the lists which were made from time t time (notably the rabbinic Seven Noachide Laws) to express basic human morality. neither the dietary laws (kashrut) nor the purity laws were regarded as obligatory for non-Israelites. Nations or peoples castigated in the Bible for immorality...were never accused of breaches of purity, but only of basic morality

(pp.vii-viii, Hyam Maccoby, Ritual and Morality: the Ritual Purity System and its place in Judaism)