Rambam - 1 Chapter a Day

The term used by the Rambam is taken from Numbers 19:15. See Chapter 21, where this subject is discussed in detail.

It must be emphasized that whenever it is said that a house or an ohel becomes impure, the intent is that the inner space of the house or the ohel, becomes impure. The house itself does not contract impurity.

And humans. This law is relevant to contemporary halachah when there is a corpse in the inner ohel and a priest in the outer one.

For the impurity will seek to depart from the inner ohel, as it were, and thus enter the larger ohel, as explained in ch. 7.
The Ra’avad explains that the law stated by the Rambam applies only when the inner ohel is fit to contract impurity or when there is no other opening through which the impurity can depart from the inner ohel. If, however, it is not fit to contract impurity itself and there is a window or entrance through which the impurity can depart, the larger ohel does not contract impurity.

Or animal.

Mikveot 10:8 explains that this applies in an instance where a person swallowed a pure ring, contracted the impurity associated with a corpse, had the ashes of the red heifer sprinkled upon himself, immersed himself and then vomited the ring. If he had not gone through the process of purification, the ring would not be pure, because it would contract ritual impurity by touching his body as he vomits it.

From spreading or from being contracted. See also Chapter 1, Halachah 8.

Thus if there is the flesh of a corpse in their intestines, the ohel becomes impure. It is as if the flesh from the corpse is in a container [Rav Kapach’s version of the Rambam’s Commentary to the Mishnah (Ohalot 11:7)]. If there is a k’li in their intestines, the k’li becomes impure.

Ritual slaughter involves slitting the gullet and the windpipe. For the slaughter of a fowl to be effective, it is necessary that merely the majority of one of these two organs be slit. For the slaughter of an animal to be effective, the majority of both organs must be slit (Hilchot Shechitah 1:9, 3:5).

This concept is reflected in similar rulings in Hilchot Tum’at Ochalin 2:6, 3:4. Nevertheless, in Chapter 1, Halachah 15, and other sources, it is stated that an animal in its death throes is considered alive. It is possible to explain that this is a stringency ordained with regard to the impurity of foods.

I.e., once the flesh of a corpse has been digested, it no longer imparts impurity. The Rambam is thus asking how long the digestive process of these animals takes.

See Shabbat 155b which explains that the digestive process of a dog is particularly slow. In his Commentary to the Mishnah (loc. cit.), the Rambam mentions that it is possible that this lengthy time applies only with regard to the digestion of the flesh of a corpse.

For it is considered as if it had decomposed already.

For they are intact.

Our translation of this and the following terms are taken from the Rambam’s Commentary to the Mishnah (Keilim 9:6).

At the top of a wooden spindle, there was usually a metal hook. In this instance, the hook was pushed into the wood so that it was not visible [the Rambam's Commentary to the Mishnah (Keilim 9:6)].

A wooden rod used to direct the animals pulling the plow so that they do not deviate from the path (ibid).

The ring was in the clay from which the brick was made and it was fired in the kiln together with it (ibid.).

Moreover, even when there is a sealed cover, iron utensils are not saved from impurity, as will be explained.

In the Talmudic era, the ovens were made of earthenware and clay was often placed on the top or the bottom of the oven to reinforce it (ibid.:1).

Since they are part of the structure of the oven itself, their status is dependent on it (ibid.).

The rationale is that they are on the sides of the jug and the sides do not need a clay seal. Thus this clay is not considered as part of the jug. Instead, it is as if the keilim were attached to a jug with clay.

Since they do not project into the jug’s inner space, they are considered as integral part of the covering and not as a separate entity. Needless to say, they do not become impure if they are in the midst of the clay over the jug’s opening (ibid.).

Chapter 23, Halachah 1.

As long as they are covered by clay, they are not considered as having entered the inner space of the jug.

Chapter 24, Halachah 2.

Which is considered as a separate entity entirely.

And there is a cubic handbreadth of empty space below the partition. Here we are speaking of an instance where the entrance to the house is above the partition. See also Chapter 24, Halachah 2. In contrast to this halachah, there the Rambam speaks of an instance where the entrance to the house is below the partition.

Halachah 1. The Ra’avad objects to the Rambam’s ruling, stating that there are instances when an ohel prevents the spread of impurity. The Kessef Mishneh agrees, but explains that this principle would apply were the partition to separate the house into two portions vertically across its entire inner space. Here, however, it does not. Hence, since the impurity seeks to leave the house, it passes above the partition and imparts impurity to the space there.

In this instance, the impurity does not seek to go under the partition, for its easier path is to depart from the house.

I.e., it has a domelike structure above it [the Rambam’s Commentary to the Mishnah (Ohalot 3:7)].

Although later, we will use the term a cubic handbreadth, each of the coordinates must be at least a handbreadth (ibid.).

For the easiest path is for impurity to depart through the entrance to the drain, rather than enter the house (ibid.). Diagram

The rationale is that the impurity “seeks to depart and not to enter.” Hence, its most direct path is to leave through the entrance of the house. This ruling leads to the general principle that a secondary opening that is a cubic handbreadth in size intervenes and does not allow impurity to enter (ibid.).

For there is no other path for the impurity to depart (ibid.).

Nevertheless, since it is a cubic handbreadth in size, it is considered as distinct from the house.

Since it is not a cubic handbreadth in size, it is not considered as distinct entity.

As stated in the previous halachah.

I.e., anything less than an olive-sized portion.

I.e., the sum of the two portions. There is no need for the two portions to be together. See the Rambam’s Commentary to the Mishanh (Ohalot 8:6).

As stated in Halachah 1.

And the seal prevents the impurity from entering, as stated in the following chapter.

Since it is open, impurity can enter it.

Because it is in a sealed covering.

Because the impurity from the inner or middle room seeks to depart and passes through the outer room.

Because a full measure of impurity is not contained within them and the impurity from the outer room will not enter further into the house. In his gloss to this mishnah, Tifferet Yisrael emphasizes that this ruling applies provided the doors between the rooms are closed. If they are opened, the rooms are considered as a single entity. This ruling is quoted by the Shulchan Aruch, Yoreh De’ah 371:3. Diagram