Rambam - 1 Chapter a Day

A person — and also a k’li.

The commentaries note that frequently the Talmud (Chagigah 11a, et al.) cites the source as Leviticus 15:5: “And he shall wash in water.” As mentioned previously, the Rambam often cites other verses than those cited by the Talmud as prooftexts if they appear to him as closer to the simple interpretation of the concepts (Y ad Malachi, K’lallei Rambam).

Our Sages (Chagigah 11a, et al.) also derive this concept from the verse cited in the previous note: “And he shall wash in water,” i.e., water that can contain his entire body. Apparently, the Rambam considers this citation as merely an asmachta, a support conceived by the Sages.
Even if a person is short and his or her body could be covered by a small measure, a mikveh is not effective unless it is of the above size (Siftei Cohen 201:3). The same measure is required for the immersion of implements.

A se’ah is 8.3 liter in modem measure according to Shiurei Torah and 16.2 liter according to Chazon Ish. When calculating the 40 se’ah that comprise a kosher mikveh, it is customary to follow the stringent view and require 650 liter.

The halachic definition of “drawn” is water separated from its source due to human activity (see Chapter 5, Halachah 7) or water which passed over or was contained within a receptacle as a result of conscious human activity (see Chapter 6, Halachah 1).

As the Beit Yosef, Yoreh De’ah 201, writes, although there are many Rishonim who support the Rambam’s position, there are also many who differ and maintain that, even according to Scriptural Law, drawn water is invalid for a mikveh. This view is quoted by the Rama (Yoreh De’ah 201:3).

A log is 344 cc. according to Shiurei Torah and 600 cc. according to Chazon Ish.

As stated in Halachah 6, this applies only when there was less than 40 se’ah in the acceptable mikveh. Once there are 40 se’ah, one can add any amount of drawn water to it without disqualifying it.

According to the Rambam, the concept that follows is not derived from the verse. Instead, it is a Rabbinic ordinance. Nevertheless, the Sages found support for their ruling in the verse cited. This is referred to as an asmachta.

I.e., it is entirely a natural phenomenon.

It is only through human effort that a cistern will be filled.

Sifra to the above verse.

For the verse associated it with a spring.

I.e., by natural means. This is not required because the verse also associated it with a cistern.

I.e., even the Rabbis would accept such a mikveh.

If, however, he placed them on the roof to collect water, the water is unacceptable for use in a mikveh, as reflected by the following halachah (see Siftei Cohen 201:94).

And thus it could be said that the person had it in mind that they would become filled with water.

Without lifting them up, as stated at the conclusion of the halachah.

I.e., if it flows from the roof into a mikveh. Since the water was not lifted up by a person, it is not considered as drawn.

Because they were lifted up by a person.

A drainage pipe itself is usually not considered as a container, either because it does not have a receptacle or because it was afftxed to the building before its receptacle was made ([the Rambam’s Commentary to the Mishnah (Mikveot 4:1)].

I.e., even when there were no clouds in the sky (ibid.).

See Hilchot Keilim 1:6.

Without lifting them up, as stated in the previous halachah.

Since it can be assumed that the drainpipe will conduct water, placing the receptacles there is considered equivalent to filling them by hand.

Since it is considered as if he gathered the water in the buckets, the fact that he spills it out without lifting them up is not significant.

And then claim to have forgotten them. This is one of the eighteen decrees passed on the eventful day when the students of the School of Shammai outnumbered the students of the School of Hillel and ordained rulings according to their more stringent approach (Shabbat 16b).

And threatening rain.

Since it is highly likely that it will rain in such a situation, it is considered as if he purposely filled the buckets with water.

One must, however, break the containers or turn them over without lifting them up, as stated in the previous halachah and in the final clause of this halachah.
Since the containers were placed there before the sky became overcast, the person’s action of placing the buckets there is not considered equivalent to filling them by hand.

Even though the person's intent was to have the buckets filled, since the sky cleared, he is considered to have diverted his attention and the water is acceptable (Kessef Mishneh). Other Rishonim offer a different interpretation of the passage in Shabbat on which the Rambam’s decision is based and their view is accepted by the Shulchan Aruch (Yoreh De’ah 201:41).

I.e., he was applying lime to seal the walls of the mikveh.

I.e., afterwards, rain descended, filling the mikveh and the container (Siftei Cohen 201:95).

Releasing the water into the mikveh. In this instance, turning the container over, even if one does not lift it up, is not sufficient, because there was more human involvement in the process of filling the container (Turei Zahav 201:52)

I.e., that they absorb the water so that they will not absorb other liquids stored in them afterwards (ibid.:53).

I.e., the water of the mikveh diffused through the walls of the container, filling it.

In contrast to the previous clause where it is necessary that some water remain in the mikveh, here none is required, because the person had no desire for the containers to become filled with water. On the contrary, this was against his will (ibid.:54).

I.e., one had begun collecting acceptable water in a mikveh, but the total quantity had not reached 40 se’ah. Thus the mikveh had not become acceptable.

Not only is the mikveh unacceptable for immersion, all of the water must be drained from the mikveh before acceptable water can be collected there again. See Chapter 5, Halachah 6.

Creating an acceptable mikveh.

For the addition of the extra drawn water does not disqualify the mikveh, even if the majority of the mikveh’s water is drawn (Shulchan Aruch, Yoreh De’ah 201:15).

This technique, referred to as zeriyah, is one of the methods through which the mikvaot commonly used for immersion are made. To explain: Most of the mikvaot in which people immerse today are not pools from rainwater or natural spring water. What is done? According to the method of zeriyah, a pool of rainwater comprising 40 se'ah is collected and then ordinary tap water is passed through that pool, causing it to overflow into a second mikveh pool as the Rambam states here. That second pool is used for immersion. The water is drained from it from time to time to prevent it from becoming filthy and then the pool is filled again through the above method. See also the notes to the following halachah.

Since the mikveh was acceptable, the addition of drawn water does not disqualify it.

As the Kessef Mishneh emphasizes, this last point reflects a difference of opinion between the Rambam and Rabbenu Asher. Rabbenu Asher and many other authorities who support his position maintain — and indeed the previous halachah would lead to this conclusion — that no matter how much water is added and subtracted, as long as there are always 40 se’ah of water in it, the mikveh is acceptable, since originally, it contained 40 se’ah of acceptable water.
In his Kessef Mishneh, Rav Yosef Caro maintains that the Rambam also agrees that the mikveh is theoretically acceptable in this instance as well. Nevertheless, according to his view, the Sages (Yevamot 82b) disqualified such a mikveh as a Rabbinic safeguard, because of the impression it would create. In his Shulchan Aruch, Yoreh De’ah 201:24, he accepts the opinion of Rabbenu Asher and those who support his perspective. Nevertheless, the Siftei Cohen 201:63 suggests following the stringencies of the Rambam’s view. In respect to his ruling and that of the Ra’avad who is even more stringent, there are authorities who prefer not to use the method of zeriyah (see note 42) to create an acceptable mikveh.

But not on a k’li (Shulchan Aruch, Yoreh De’ah 201:46). The water must flow on the ground for at least three handbreadths (ibid.:45).

If, however, initially, drawn water was caused to flow on the ground into a mikveh, before there were 20 se’ah of acceptable water there, this leniency is not applicable (Rama, Yoreh De’ah 201:44).

See Chapter 6 for a discussion of which conduits disqualify a mikveh and which do not.

As the Kessef Mishneh emphasizes, this represents a further leniency than the previous clause, because in this instance, the entire quantity of water was already designated as unacceptable before it was caused to flow.

See Beit Yosef, Yoreh De’ah 201, who mentions this opinion in the name of Rabbenu Yitzchak Alfasi.

Temurah 12b.

Which are not considered as receptacles.

See also the Rambam’s Commentary to the Mishnah (Mikveot 4:4), where, when discussing the law cited in the following halachah, he explains that it represents a refutation of the perspective of the sages of the west.

This represents a further leniency because the acceptable water did not exist as a separate entity before it became mixed with the drawn water.

Without flowing on the ground first.