The rationale is that it is only keilim, useful articles, that are susceptible to ritual impurity, not raw materials. Until the fashioning of a k’li is completed, it is not placed in this category. As will be explained, however, there are times a k’li can be considered as finished even though it is in an intermediate state.
In his Commentary to the Mishnah (Keilim 16:1), the Rambam states that this refers to a specific type of fish called alsafon whose skin is very bumpy. Rubbing the keilim with this skin would smooth them and polish them. Generally, until this final preparatory stage was completed, these articles were not considered as ready for use.
For the work involved in making them was completed.
Baskets woven from reeds or the like (ibid.:2).
And thus become susceptible to impurity.
A border is made around the ends of the weave of the reeds, tying them together, so that the weave will not be undone (ibid.:2).
For until then, it is not fit to be used for the purpose for which it was intended.
Our translation is based on Rav Kapach’s translation of the Rambam’s Commentary to the Mishnah (Keilim 16:3).
In his Commentary to the Mishnah (ibid.:16:3), the Rambam explains that reeds or palm bast would be woven into a very long reel, at times 50 meters long. Afterwards, they would sew the woven leaves into a container of the shape and size they desired. These containers would be used to store wheat and flour in mills. Similarly, the containers the Rambam proceeds to mention are all fashioned by taking a reel of woven reeds or the like and shaping it into the form of the desired k’li. At times, the reel of woven reeds would be wound more than once around the base of the container to raise the height of the container.
And a base sewed to the basket (ibid.).
Tifferet Yisrael and other commentaries to the Mishnah explain the difference between the terms dor and tzifirah used by the mishnah and the Rambam as follows: Tzifirah imply circles made by separate lengths of reeds, while dor implies that the same length of reed is circled several times without separation. There is, however, no indication of such an interpretation in the Rambam’s words.
Which is susceptible to ritual impurity, as reflected by Chapter 22, Halachot 1, 12.
Our translation is based on the Rambam’s Commentary to the Mishnah (Keilim 20:2).
The Rambam is borrowing — out of context — the wording of Isaiah 44:13.
From Chulin 25a-b, it appears that the rationale is that since these articles are of little value, it is likely that they will be used even before the finishing touches mentioned above are concluded. Hence, they are considered as “having been fashioned completely” even before then.
In his Commentary to the Mishnah (Keilim 12:8), the Rambam writes that unless this wood is planed, it is unusable, because it is likely to produce splinters.
Chulin 25b mentions a difference of opinion between two Sages, Rabbi Yochanan and Rav Nachman, that relates to the status of unfinished bone utensils without coming to a definite ruling. The Rambam appears to have accepted the view of Rav Nachman based on his own processes of deduction.
The Ra’avad questions the Rambam’s explanation, noting that Rav Nachman compares bone keilim to those made of metal, not to those made of boxwood. The Kessef Mishneh maintains that the Rambam is not accepting Rav Nachman’s view over Rabbi Yochanan’s, but rather accepting the decision the Talmud attributes to Rav Nachman’s perspective for an entirely different reason: that like boxwood keilim, those made from bone are not considered as useful until they are finished.
The Kessef Mishneh interprets this as referring to the kupat mentioned in Keilim 22:9. Since it does not have a receptacle, nor does it conform to the accepted shape of a particular k’li, it is not placed in that category, for the laws of impurity apply to “keilim,” not to every type of useful object.
Our translation is based on the Rambam’s Commentary to the Mishnah (Keilim 15:2). Similarly, the version of the Hebrew text used depends on that source and the authoritative manuscripts of the Mishneh Torah. The standard printed text has a slightly different version.
Which are much smaller, for they are employed for personal not wholesale use.
For they do not have a specific shape or form so that they can be considered as a k'li.
For an ordinary block of wood is not painted. In his Commentary to the Mishnah (ibid.:15:2), the Rambam emphasizes that the impurity of these keilim—and the others mentioned previously—are all Rabbinic in origin. According to Scriptural Law, wooden keilim that do not have a receptacle are all pure. See Chapter 1, Halachah 10.
In his Commentary to the Mishnah (ibid.), the Rambam identifies this term with the “service vestments” (Exodus 39:1) used in the Sanctuary.
The Kessef Mishneh asks an obvious question: It appears that this accessory contains a receptacle for water. If so, why is the accessory used by ordinary private persons pure? The Kessef Mishneh therefore explains that this accessory is a board on which a bowl of water is placed. Bakers designate a specific board for this purpose, while ordinary private persons use any available piece of wood. Rambam LeAm explains that a baker's accessory contains a receptacle for water, because that is necessary due to the quantity of loaves they produce. A homemaker, by contrast, uses an ordinary flat board upon which he pours water. That is sufficient for the few loaves he makes.
For it is now considered as a receptacle.
For it is no longer considered as a receptacle.
For it is a container. Indeed, the term used by the mishnah (Keilim 15:3) to describe it, yam, literally, “sea,” indicates that.
In his Commentary to the Mishnah, the Rambam states that we are forced to say that the form of the utensil used by private persons causes it to be pure. He does not explain how- and it is difficult to understand how- for if, like the k'li used by the professionals, it is a container, seemingly, it would be susceptible to impurity.
Our translation is based on the Rambam’s Commentary to the Mishnah (Keilim 15:5).
Pushing them from the side rather than lifting them up.
Loops from which utensils are hung on hooks, pegs, or the like. This is referring to loops that are not permanently attached to the utensils for which they are used.
Since the loops are not permanently attached to the utensil, their status is considered independently and, in and of themselves, they are not considered as keilim. Hence, even if the k'li that hangs from them comes in contact with a source of ritual impurity, they are considered as pure. If, however, they are permanently attached to the k'li that hangs from them, they are considered as part of that k'li and their status is dependent on its status.
These staffs were used by customs’ inspectors to probe loads of straw to see if grain was being hidden inside of it to avoid paying the taxes due [the Rambam’s Commentary to the Mishnah (Keilim 15:4)].
I.e., the person performing the task inserts his hand through the loop and uses it for support while carrying out the task (ibid.).
We have used the popular translation of the term although Rav Kappach’s translation of the Rambam’s Commentary to the Mishnah (Keilim 15:6) explains that it refers to an ancient wind instrument.
The Kessef Mishneh (based on the gloss of R. Ovadiah of Bartenura to the above Mishnah) maintains that there would be cavities in these lyres in which the musicians would store money and the like.
For these lyres were not made with such cavities (ibid.).
Our translation is taken from the Rambam’s Commentary to the Mishnah (op. cit.). It is impure, because it has a receptacle like the lyres mentioned previously.
In his Commentary to the Mishnah (op. cit.), the Rambam explains that this term refers to a prosthetic leg and, by association, to a harp made in the form of such an object. This explanation resolves the question raised by the Ra’avad in his gloss.
Here also our translation is taken from the Rambam’s Commentary to that source.
Our translation is based on the Rambam’s Commentary to the Mishnah (Chulin 3:3).
In his Commentary to the Mishnah (Keilim, 15:6), the Rambam explains that in that era, the traps used for these animals were made in a form that necessitated such a ruling.
See the Rambam’s Commentary to the Mishnah (Keilim 16:5) for details concerning all the terms used in this halachah.
The Ra’avad offers a different rationale: Such containers are not intended to be carried.
Because it is not a lasting entity.
For such a divider will remain for a significant time.
In his Commentary to the Mishnah (op. cit.), the Rambam explains that fresh dates and the like are placed in such containers when they are being sold so that they will not soil the hands of those who handle them.
Since the pocket is being used both to deposit fruit and remove it, it is considered as a container.
For it is obvious that it is being used only temporarily and is not considered as a container for ongoing use. From this, we see that disposable utensils are not susceptible to ritual impurity.
A cattle-horn or the like that was hollowed out and used as a drinking vessel or the like.
For, in its natural shape, it is not commonly used as a container.
Since it was susceptible to ritual impurity beforehand and can be used as a container in its present position, it is susceptible to impurity even though it has become permanently attached to an object that is not susceptible to ritual impurity.
Or its wall was affixed to the base of the chest, for in this way as well, it cannot serve as a container [the Rambam’s Commentary to the Mishnah (Keilim 20:5)].
Like the chest itself. The Kessef Mishneh quotes Rav Yosef Corcus who emphasizes that this ruling applies only when the chest is oversized and, hence, not susceptible to impurity.
In his Commentary to the Mishnah (Keilim 23:5), the Rambam explains that this refers to a basket that is submerged in the water in which fish are snared.
From a comparison to the following halachah, it appears that the Rambam does not consider these objects to have the form of keilim.
In his Commentary to the Mishnah (op. cit.), the Rambam explains that this refers to a board on which there is a support of wood held up by a rope. When the hunter sees a fowl rest on the board, he pulls the rope and the wooden support falls on the fowl.
I.e., a body of water is dammed so that the fish will collect in one place. Afterwards, the water is allowed to flow out and thus the fish will be caught.
We are speaking about benches made from a board with holes into which legs are inserted when one desires to use them. If one does not desire to use them, the legs and the boards are kept separate. Since they are not affixed to the bench permanently, it is not considered as a k’li.
I.e., a seat whose legs are permanently attached to it.
As the Rambam emphasizes in his Commentary to the Mishnah (Keilim 22:10), when even one of the legs of a two-legged bench are made from stone, it is considered as a stone utensil and no longer susceptible to ritual impurity.
