1. Any [water] that mingles with a mikveh is like the mikveh. [In the case of] holes in a cave or cracks in a cave, one may immerse [something] in them however they are. [But in the case of] a dugout [under] a cave, one may not immerse [anything] in it unless there is an opening the size of a waterskin tube. R’ Yehudah said: When [is this so]? When it supports itself. But if it does not support itself, one may immerse [something] in it however it is.

2. [If] a bucket was full of utensils and one immersed them, they become tahor. [But] if he did not [need to] immerse it, [then] the waters are not [considered] mingled, unless they mingle as much as the size of a waterskin tube.

3. [If] there are three mikvaos, one containing twenty se’ah [of rainwater] and another [also] containing twenty se’ah [of rainwater], and the other containing twenty se’ah of drawn water, and the one of drawn water is at the side, and three persons went down and immersed themselves therein and [the waters] became mingled, the mikvaos are tahor and those that immersed themselves therein are tahor. [If] the one of drawn water was in the middle, and three persons went down and immersed themselves therein and [the waters] became mingled, the mikvaos are as they were and those that immersed themselves are as they were.

4. [If] a sponge or bucket contained three lugin of water, and it fell into a mikveh, it does not disqualify it, because all they said was, ‘‘Three lugin that fell in.’’