An unclean man who went down to immerse himself: If it is doubtful whether he did immerse himself or not; And even if he did immerse himself, it is doubtful whether the mikveh contained forty seahs or not; And if there were two mikvehs, one containing forty seahs but the other not containing forty seahs, and he immersed himself in one of them but he does not know in which of them he immersed himself, In such a doubt he is unclean.

If a mikveh was measured and was found lacking [in its prescribed quantity], all things which had been purified in it, whether in private domain or in a public domain, are accounted unclean retroactively. To what does this rule apply? To a serious uncleanness. But in the case of a lesser uncleanness, for instance if he ate unclean foods or drank unclean liquids, or if his head and the greater part of his body entered into drawn water, or if three logs of drawn water fell on his head and the greater part of his body, and he then went down to immerse himself and he is in doubt whether he immersed himself or not, or even if he did immerse himself there is [still] a doubt whether the mikveh contained forty seahs or not, or if there were two mikvehs, one containing forty seahs and not the other, and he immersed himself in one of them but does not know in which of them he immersed himself, in such a doubt he is accounted clean. Rabbi Yose considers him unclean, for Rabbi Yose says: anything which is presumed to be unclean always remains in a condition of unfitness until it is known that it has become clean; but if there is a doubt whether a person became unclean or caused uncleanness, it is to be accounted clean.

The case of a doubt about drawn water which the sages have declared clean;If there is a doubt whether [three logs of drawn water] fell into the mikveh or not, Or even if they did fall in, there is a doubt whether [the mikveh] contained forty seahs or not, Or if there were two mikvehs one of which contained forty seahs and the other did not, and drawn water fell into one of them and it is not known into which of them it fell, In such a doubt it is accounted clean, because there exists [a possibility] on which we may depend [in declaring it clean]. If they both contained less than forty seahs, and [drawn water] fell into one of them and it is not known into which of them it fell, in such a doubt it is accounted unclean, because there exists no [possibility] on which we may depend [in declaring it clean].

Rabbi Eliezer says: a quarter-log of drawn water in the beginning makes the mikveh invalid, and three logs on the surface of the water. But the sages say: both in the beginning and at the end, the measure [which makes the mikveh invalid] is three logs.

If there were three cavities in a mikveh each holding a log of drawn water, if it is known that forty seahs of valid water fell in before reaching the third cavity, [such a mikveh is] valid; otherwise it is invalid. Rabbi Shimon declares it valid, since it resembles a mikveh adjoining another mikveh.

If one scraped mud to the sides and then three logs [of water] were drawn out from it [from the mud], [the mikveh is still] valid. But if removed the mud away and three logs were drawn from it [into the mikveh] it becomes invalid. Rabbi Shimon pronounces it valid, since there was no intention to draw [the water].

If one had left wine-jars on the roof to dry and they became filled with water: Rabbi Eliezer says: if it was the season of rain and there was [in the cistern] a little water, one may break the jars; otherwise one may not break them. Rabbi Joshua says: in either case one may break them or tilt them over, but one may not empty [them into the cistern].

If one had arranged wine-jars in a cistern and they became filled with water, even though the water of the cistern was all soaked up, they may be broken.

A mikveh which contains forty seahs of water and mud [combined]: Rabbi Eliezer says: one may immerse objects in the water but one may not immerse them in the mud. But Rabbi Joshua says: in the water and also in the mud. In what kind of mud may objects be immersed? Mud over which water floats. If the water was on one side only, Rabbi Joshua agrees that objects may be immersed in the water but may not be immersed in the mud. Of what kind of mud have they spoken? Mud into which a reed will sink of itself, the words of Rabbi Meir. Rabbi Judah says: [mud] in which a measuring-rod will not stand upright. Abba Elazar ben Dulai says: [mud] into which a plummet will sink. Rabbi Eliezer says: such as will go down into the mouth of a jar. Rabbi Shimon says: such as will enter into the tube of a water- skin. Rabbi Elazar bar Zadok says: such as can be measured in a log measure.