There are six degrees of mikvaot, each superior to the other. The water of pools [smaller than 40 seah] if an unclean person drank of it and then a clean person drank of it, he becomes unclean; If an unclean person drank of it and then drew water from it in a clean vessel, [the vessel] becomes unclean; If an unclean person drank of it and then a loaf of terumah fell in: If he washed [his hands] in it, it becomes unclean; But if he did not wash [his hands] in it, it continues clean.

If one drew water from it in an unclean vessel and then a clean person drank [out of the pit], he becomes unclean. If one drew water [from it] in an unclean vessel and then drew water from it in a clean vessel, it becomes unclean. If one drew water [from it] in an unclean vessel and a loaf of terumah fell in: If he washed [his hands] in it, it becomes unclean; But if he did not wash [his hands] in it, it is clean.

If unclean water fell into it and a clean person drank of it, he becomes unclean. If unclean water fell into it and then water was drawn from it in a clean vessel, it becomes unclean. If unclean water fell into it and a loaf of terumah fell in: If he washed [his hands] in it, it becomes unclean; But if he did not wash [his hands] in it, it is clean. Rabbi Shimon says: it becomes unclean whether he washed in it or whether he did not wash in it.

When do they become clean?Bet Shammai say: when their contents have been increased [by more than the original quantity] and they overflow. Bet Hillel say: when their contents have been increased [by more than their original quantity] even if they do not overflow. Rabbi Shimon says: when they overflow although their contents have not been so increased. [These] are valid [for preparing dough] for hallah and for the washing of the hands.

Superior to such [water] is the water of rain flows which have not stopped. If an unclean person drank of it and then a clean person drank of it, he is clean. If an unclean person drank of it and water was then drawn from it in a clean vessel, it is clean. If an unclean person drank of it and a loaf of terumah fell in, even if he washed his hand in it, it is clean. If one drew water from it in an unclean vessel and then a clean person drank [out of the pool], he is clean. If one drew water from it in an unclean vessel and a loaf of terumah fell [into the pool], even if he washed his hands in it, it is clean. If unclean water fell into it and a clean person drank of it, he is clean. If unclean water fell into it and one drew water from it in a clean vessel, it is clean. If unclean water fell into it and a loaf of terumah fell in, even if he washed his hands in it, it is clean. [All such water] is valid for terumah and for the washing of the hands.

Superior to such [water] is [the water of] the mikveh containing forty seahs, for in it people may immerse themselves and immerse other [things]. Superior to such [water] is [the water of] a spring whose own water is little but has been increased by a greater quantity of drawn water. It is equivalent to the mikveh in as much as it may render clean by standing water, and to an [ordinary] spring in as much as one may immerse in it whatever the quantity of its contents.

Superior to them are "smitten waters" which can purify even when flowing [on the ground]. Superior to them are "living waters" for in them there is immersion for zavim and sprinkling for metzoraim, and they are valid for the preparation of the hatat waters.