The fathers of impurity are a: sheretz, semen, [an Israelite] who has contracted corpse impurity, a metzora during the days of his counting, and the waters of purification whose quantity is less than the minimum needed for sprinkling. Behold, 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.

Above them is one who had intercourse with a menstruant, for he defiles the bottom [bedding] upon which he lies as he does the top [bedding]. Above them is the issue of a zav, his spit, his semen and his urine, and the blood of a menstruant, 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 zav, for a zav 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.

Above the zav is the zavah, for she conveys impurity to the man who has intercourse with her. Above the zavah is the metzora, for he conveys impurity by entering into a house. Above the metzora 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 ohel (tent) whereby all the others convey no impurity.

There are ten [grades of] impurity that emanate from a person:A person before the offering of his obligatory sacrifices is forbidden to eat holy things but permitted to eat terumah and [second] tithe. If he is a tevul yom he is forbidden to eat holy things and terumah but permitted to eat [second] tithe. If he emitted semen he is forbidden to eat any of the three. If he had intercourse with a menstruant he defiles the bottom [bedding] upon which he lies as he does the top [bedding]. If he is a zav who has seen two discharges he conveys impurity to that on which he lies or sits and is required to undergo immersion in running water, but he is exempt from the sacrifice. If he saw three discharges he must bring the sacrifice. If he is a metzora that was only enclosed he conveys impurity by entry [into an ohel] but is exempt from loosening his hair, from rending his clothes, from shaving and from the birds offering. But if he was a confirmed metzora, he is liable for all these. If a limb on which there was not the proper quantity of flesh was severed from a person, it conveys impurity by contact and by carriage but not by ohel. But if it has the proper quantity of flesh it conveys impurity by contact, by carriage and by ohel. A "proper quantity of flesh" is such as is capable of healing. Rabbi Judah says: if in one place it has flesh sufficient to surround it with [the thickness of] a thread of the woof it is capable of healing.

There are ten grades of holiness: the land of Israel is holier than all other lands. And what is the nature of its holiness? That from it are brought the omer, the firstfruits and the two loaves, which cannot be brought from any of the other lands.

Cities that are walled are holier, for metzoras must be sent out of them and a corpse, though it may be carried about within them as long as it is desired, may not be brought back once it has been taken out.

The area within the wall [of Jerusalem] is holier, for it is there that lesser holy things and second tithe may be eaten. The Temple Mount is holier, for zavim, zavot, menstruants and women after childbirth may not enter it. The chel is holier, for neither non-Jews nor one who contracted corpse impurity may enter it. The court of women is holier, for a tevul yom may not enter it, though he is not obligated a hatat for doing so. The court of the Israelites is holier, for a man who has not yet offered his obligatory sacrifices may not enter it, and if he enters he is liable for a hatat. The court of the priests is holier, for Israelites may not enter it except when they are required to do so: for laying on of the hands, slaying or waving.

The area between the porch (ulam) and the altar is holier, for [priests] who have blemishes or unkempt hair may not enter it. The Hekhal is holier, for no one whose hands or feet are unwashed may enter it. The Holy of Holies is holier, for only the high priest, on Yom Kippur, at the time of the service, may enter it. Rabbi Yose said: in five respects the area between the porch and the altar is equal to the Hekhal, for those afflicted with blemishes or with a wild growth of hair, or who have drunk wine or whose hands or feet are unwashed may not enter there, and the people must keep away from the area between the porch and the altar when the incense is being burned.