Levels of Impurity

1. The fathers of impurity [i.e., the highest-level sources of impurity] are: a swarming creature [see Leviticus 11:29–38], semen [see Leviticus 15:16–17], [an Israelite] who has contracted corpse impurity [see Numbers 19:11–20], a person with skin disease during the days of his counting [see Leviticus 13–14], and the waters of purification [containing the ashes of a red heifer] whose quantity is less than the minimum needed for sprinkling [see Numbers 19:21]. These convey impurity to people and vessels by contact and to earthenware by presence within their airspace, but they do not convey impurity by being carried.

2. Above them are the carrion of a pure animal [see Leviticus 11:24–28, 39–40] and waters of purification whose quantity is sufficient to be sprinkled, for these convey impurity to a person [even] by being carried so that he in turn conveys impurity to clothing by contact. Clothing, however, is free from impurity where there was contact alone.

3. Above them is one who had intercourse with a menstruant, for he defiles the bottom [bedding] on which he lies as he does the top [bedding] [see Leviticus 15:24]. Above them is the issue of a man with a genital discharge, his spit, his semen, and his urine [see Leviticus 15:2–12], and the blood of a menstruant [see Leviticus 15:19–23], for they convey impurity both by contact and by carrying. Above them is an object on which one can ride, for it conveys impurity even when it lies under a heavy stone. Above the object on which one can ride is that on which one can lie, for contact is the same as its carrying. Above the object on which one can lie is the man with a genital discharge, for a man with a genital discharge conveys impurity to the object on which he lies, while the object on which he lies cannot convey the same impurity to that upon which it lies.

4. Above the man with a genital discharge is the woman with an irregular flow [see Leviticus 15:25–27], for she conveys impurity to the man who has intercourse with her. Above the woman with an irregular flow is the person with skin disease, for he conveys impurity by entering into a house. Above the person with skin disease is a [human] bone the size of a barley grain, for it conveys impurity for seven days. More strict than all these is a corpse, for it conveys impurity by tent¹ [see Numbers 19:14–15], whereby all the others convey no impurity.