One-Page Learn · The Halachos at a glance
מקואות
Mikvaot 8-10
Sefer Taharah · Immersion Pools · How two bodies of water become one, the six grades of water from a cistern to a living spring, and the two opposite ways the law resolves a doubt.
40
Se'ah for a valid mikveh
6
Grades of water, each above the last
2
Fingers rotating: the joining measure
3
Lugim of drawn water that disqualify
Ch 8What Counts as Touching
- Water touching the mikveh is the mikveh. Cavities at the opening and even animal footprints at the edge may be used for immersion if they share a point of contact the size of the mouthpiece of a drinking pouch; cavities and crevices at the side need only the slightest contact. A needle left on the steps is purified by raising a wave over it (8:1-3)
- The measure, exactly. A circle whose diameter lets two average fingers rotate inside it, not the thumb but the first two on the palm. Anything present in that hole reduces the measure, even something created out of the water itself, and a doubt about the measure means the pools are not joined, because the primary obligation to immerse is Scriptural (8:6)
- A pipe joins across a hairsbreadth; a current joins nothing. An earthenware or lead pipe filled from a valid pool and set to touch another makes them one, even if the waters intermingle by a hairsbreadth. But three basins in a wadi holding 20, 40 and 20 se'ah with rain running through all three stay separate, and only the middle is valid, since flowing water does not join mikveot unless it collects in one place (8:7-8)
- Exactly forty is exactly forty. Two people immerse in sequence in a pool of precisely 40 se'ah: the first is pure, the second is not, because water left on the first man's body, and even his feet still in the water do not help. A thick sponge immersed and lifted, still touching the surface, keeps all the water intermingled and the next man pure. Soft mud a cow would drink is measured in; red worms and the eye of a giant fish are fit for immersion (8:9-12)
RememberA hairsbreadth of standing contact joins two pools. A river running through three of them joins none.
Ch 9Six Grades, From a Cistern to Living Water
- The ladder. (1) Water collected in a pit or cistern, even drawn and under 40 se'ah, presumed pure for dough and for washing hands from a vessel. (2) Rainwater still flowing while the mountains gush, undrawn but under 40, fit for terumah and for immersing impure water. (3) Forty undrawn se'ah: everyone immerses, every impure vessel, except a male zav (9:1-5)
- The three springs on top. (4) A small spring with drawn water added: needs a reservoir like a mikveh, needs no minimum like a spring. (5) A spring gone bitter or salty: purifies while flowing. (6) A spring of living water: the only place a male zav immerses, and the only source for the metzora's purification and for sanctifying the water for the red heifer's ashes (9:6-8)
- Spring against mikveh, three differences. A mikveh needs 40 se'ah, a spring needs no measure at all. A mikveh purifies only in a collected reservoir, a spring purifies while flowing. A mikveh does nothing for a zav, a spring of living water does. All the seas purify, yet serve for none of those three (9:8, 9:12)
- Flowing, dripping, and in the air. Water flowing from a spring is the spring; water that merely drips is only a mikveh and needs 40 se'ah standing in one place. A conduit must not be susceptible to impurity even rabbinically, though a fresh green nut shell may turn the flow since it is no container. Cascading rainwater is unfit while it runs and fit once containers are set as walls behind which 40 se'ah collects. A wave purifies only when both ends touch the earth, never in the air and never at its crest (9:13-18)
RememberA mikveh is a quantity. A spring is a source. One needs forty se'ah and stillness; the other needs neither.
Ch 10Doubt, in Two Opposite Directions
- Doubt about drawn water is lenient. Unsure whether drawn water fell in, or whether there were three lugim, or whether the pool held 40 when it fell: valid in every case. A pool left empty and found full is valid. Two pools, one of 40 and one less, three lugim into an unknown one: the valid one stays valid, since there is a factor to rely on (10:1-3)
- Unless the disqualifier is in plain view. A pipe feeding the pool with a mill beside it, and no way to know which supplied the water, is unacceptable, because the disqualifying factor is evident. If the pool holds a majority of acceptable water it is acceptable, since the doubt is only about drawn water and an established pool is already there (10:4)
- Presumptions by location. Pools in the lands of the nations are presumed invalid as drawn. Pools inside a city's gates in Eretz Yisrael are presumed invalid, since garments are washed in them and drawn water is poured in. Pools outside the gates are presumed pure, as rainwater filled them (10:5)
- Doubt about the person is stringent. Unsure whether he immersed, or whether the pool held 40, or which of two pools he used: impure, because we presume an impure person impure until proper immersion is certain. A pool later measured short renders everything immersed in it impure retroactively. The one exception is light impurity, rabbinic at its core, where he is pure despite every such doubt (10:6-8)
RememberThe pool gets the benefit of every doubt. The man gets none, because an established status is not moved by an argument.