Rambam - 1 Chapter a Day

I.e., a pipe that has a receptacle in it where water could collect.

A large barrel over which leather or parchment would be tied to be used as a float [the Rambam's Commentary to the Mishnah (Keilim 2:3)].

Here also our translation is based on the above source. The Merkevet HaMishneh states that such barrels were used for pickling olives. The Ra’avad does not accept the Rambam’s definition of this article, but the Kessef Mishneh supports the Rambam’s perspective.

The fact that one’s hand is inserted within does not cause it to be considered as a receptacle [the Rambam’s Commentary to the Mishnah (loc. cit.)].

I.e., a cover placed around the light that protects it from being blown out by the wind. It has holes on the bottom to enable air to enter (ibid.:4).

A base placed on a potter's wheel upon which keilim are fashioned. Some of these bases are flat, without borders and hence are not susceptible to impurity. Others have borders against which the clay keilim are formed. Hence, they are considered as receptacles and are susceptible to impurity (ibid.).

Because like a pipe, the intent is that liquids pass through it and not collect there.

Through which he pours rosewater and fragrant oils (ibid.).

Since the perfumer intends that a certain amount of the fragrance collect there, the funnel is considered as a receptacle. A homeowner has no such intent. Hence, it is not considered as a receptacle for him. Diagram

Because obviously, the intent was that it should serve as a receptacle.

To allow air to escape in the cooking process [the Rambam’s Commentary to the Mishnah (Keilim 2:5)]. Since it has a hole, it cannot serve as a container.

The protrusion enables it to be picked up (ibid.). If it has a protrusion, it will not be able to sit upright and will never be able to be balanced [R. Ovadiah of Bartenura (Keilim, op. cit.)].

I.e., acts as a subsidiary to another k’li.

The subsidiary k’li.

Because it is not serving an independent function.

In his Commentary to the Mishnah (Keilim 2:6), the Rambam explains that this refers to a primitive type of sprinkler. It contained a large earthenware vat with tiny holes on the bottom and a very thin neck. When a person would place his finger in the neck, no air would enter and the water would not drip through the holes. If he would remove his finger, air would enter and the water would drip out.
The Ra’avad has a different conception of this k’li and therefore differs with the Rambam’s statements here. The Kessef Mishneh justifies the Rambam’s understanding.

In the portions where there are no holes.

In his Commentary to the Mishnah (Keilim 2:9), the Rambam explains that this refers to an earthenware shaft with a receptacle at its top.

Our translation is taken from the Rambam’s Commentary to the Mishnah (Keilim 2:6). There he explains that these bases lack handles and are placed under large vessels containing water. See also Chapter 19, Halachot 1 and 9.

In his Commentary to the Mishnah (Keilim 2:3), the Rambam cites Shabbat 83b which explains this concept based on an allusion to a Biblical verse. Apparently, he later concluded that the verse is no more than an asmachta, a support, and the concept can be understood logically.

See Chapter 6, Halachah 1, and Chapter 12, Halachah 1, above.
The Ra’avad objects to the Rambam’s ruling and maintains that the remnants of not only earthenware containers, but any type of utensil are still susceptible to impurity if they can still be used for their original function. Taharat Yisrael and the Merkevet HaMishneh explain that the Rambam would also agree that other keilim are still susceptible to impurity if they can still be used for their original function. His point is that even if they are no longer useful for that purpose, but could serve as a container, they are not susceptible to impurity. By contrast, earthenware containers in such a situation are.

For it is considered as a small earthenware container [the Rambam’s Commentary to the Mishnah (Keilim 2:2)].

See Sifra to the prooftext cited.

Because, in and of itself, it is not able to serve as a container.

The term used by the Rambam and his source, Keilim 4:1, literally means “ear.” In his Commentary to the Mishnah (Keilim 4:1), the Rambam explains that we are talking about an instance that the container has a very heavy handle on one side which causes it to tip to that side.

And it can now stand on its base.

For example, the basins used to receive the blood from sacrificial animals. They did not have flat bottoms so that they would not be placed down and the blood allowed to coagulate (Hilchot Korban Pesach 1:13).

Our translation of these terms is taken from the Rambam’s Commentary to the Mishnah (Keilim 4:3).

The Rambam is explaining why these containers are exceptions to the principle stated in Halachah 10.

This expression has aroused the attention of the Ma’aseh Rokeiach and other commentaries, for it is not at all definitive. It leaves it unclear whether we are speaking about a newborn or an adult, whether the liquid must be rubbed on his entire body or only part of it.

According to his usual calculations, Shiurei Torah would consider one se’ah as 8256 cc and Chazon Ish would put that measure at 14400 cc. With regard to the measure of a se’ah for a mikveh, the Rabbis have shown greater stringency. See Hilchot Mikveot 4:1.

A Talmudic measure equivalent to 86 cc according to Shiurei Torah and 150 cc according to Chazon Ish.

This clause is an introduction to the halachot that follow. With regard to vessels that, at the outset, are too small to contain a revi’it, see Halachah 15.
The Kessef Mishneh notes that there is a difference of opinion regarding this matter in Keilim 2:2, the Rambam’s source, between Rabbi Yishmael and Rabbi Akiva and the Rambam is following Rabbi Yishmael’s opinion. As stated by the Noda B’Yehudah (Vol. II, Even HaEzer, Responsum 148), this is problematic, because the Rambam generally favors Rabbi Akiva’s view over that of Rabbi Yishmael. Moreover, in his commentary to that mishnah, the Rambam states that the halachah follows Rabbi Akiva’s view. In resolution, the Noda B’Yehudah states that the principles generally followed to determine the halachah when there is a difference of opinion between Sages of the Mishnah are not followed when the laws were not practiced in subsequent eras.

The words “or more” have attracted the attention of the commentaries, because the next clause speaks about a container larger than two se’ah.

I.e., without support from anything else.

Even though an ordinary person could use these shards as a base like a potter does, since it is unlikely that he will do so, it can be assumed that he did not consider them significant. Hence they are not considered as keilim and are not susceptible to impurity.
The Ra’avad states that he found a different version of the Rambam’s source, the Tosefta (Keilim 3:4), that rules that wherever shards are found, they are impure with the exception of those found in a potter’s shop. He favors that version. The Kessef Mishneh differs and justifies the Rambam’s interpretation.

See Halachah 8. Since the potter saves the shards, it is apparent that he considers them important for use as a base. Hence they are susceptible to impurity.