4. [If] drawn water and rainwater became mixed in a courtyard, or in a ditch, or on the steps of a cave — when the majority is valid [water], [the mikveh] is valid; but when the majority is invalid [water], [the mikveh] is invalid. Half and half, it is invalid. When so? When they became mixed before they reached the mikveh. [When, however,] they flowed [directly] into the water, if it is known that forty se’ah of valid water fell in before three lugin of drawn water came down, [the mikveh] is valid. Otherwise, it is invalid.

5. [Regarding] a trough in a rock — one may not fill into it, nor may one consecrate in it, nor may one sprinkle out of it, nor does it require a sealed cover, nor does it disqualify a mikveh. [But if] it was a vessel and one attached it [to the ground] with mortar, [then] one may fill into it, and one may consecrate in it, and one may sprinkle out of it, and it requires a sealed cover, and it disqualifies a mikveh. [If] it has a hole on the bottom or on its side so that it cannot hold any water at all, it is valid. How large must the hole be? The size of a tube of a waterskin. R’ Yehudah ben Beseira said: There was a case of Yehu’s Trough in Jerusalem that had a hole the size of a tube of a waterskin, and all the ritually pure foods in Jerusalem were prepared on its basis, and Beis Shammai sent and broke it. For Beis Shammai say: [It is not valid] until the greater part thereof is broken.

1. [If water of] a spring was directed over a trough, it is invalid. [But if] it was directed over the edge, [even] a little, [then] that which is outside [the trough] is valid, because a spring purifies, whatever its amount. [If] it was directed over a pool and it was [then] interrupted, it is like a mikveh. [If] it was made to flow again, it [remains] unfit for zavim and for metzoraim and for consecrating therefrom purification water, until one knows that the former [water] has flowed out.

2. [If] it was directed over vessels or over a bench, R’ Yehudah says: It [remains] as it was. [But] R’ Yose says: It is like a mikveh, except that one may not immerse [anything] over the bench.