Mikvaot, Chapter Three, Mishnah Four
This mishnah is a continuation of yesterday’s mishnah. It continues to deal with logs of drawn water that fell from different vessels joining together to disqualify a mikveh.
1) [If the three logs of drawn water fell in] from one vessel or from two or from three, they combine together; but if from four, they do not combine together.
2) If a man who had a seminal issue was sick and nine kavs of water fell on him, or if there fell on the head and the greater part of the body of a clean person three logs of drawn water from one vessel or from two or from three, they combine together; but if from four, they do not combine together.
3) In what case does this apply? When the second began before the first finished.
4) And in what case does [the other statement] apply? When there was no intention to increase it. But if there was an intention to increase it, if only a kortov in a whole year, they combine together to add up to the three logs.
Section one: As we learned in yesterday’s mishnah, the sages hold that the three logs can fall in from multiple sources and still disqualify the mikveh. However, if they fall in from four different vessels, since each vessel does not contain a full log (assuming equal distribution) they do not disqualify the mikveh.
Section two: The mishnah now addresses a similar issue where there is a difference between three and four. There are two situations here. The first is a sick person who can’t immerse in a mikveh. He is allowed to have nine kavs of drawn water poured on him to purify him from the impurity that is a result of a seminal emission. The second situation is a pure person upon whom fall three logs of drawn waterthis water is considered impure and will defile him.
In both of these cases, if the amount falls on his head and the greater part of his body from three different sources, they combine together to purify the man who had the seminal emission or to defile the clean person. But if from four different sources, they do not have any effect.
Section three: The pouring from different vessels joins together if the second vessel began to be poured before the first was completed. If not, they are considered separate episodes of pouring.
Section four: This section limits the cases where the separate pourings do not join, either because they were from four vessels or because the first pouring stopped before the second began. That is only true when one poured into the mikveh by accident. If one poured the drawn water into the mikveh on purpose then it disqualifies the mikveh no matter how long it takes to get the three logs into the mikveh, even if it takes a whole year, the mikveh is invalidated.