Rambam - 1 Chapter a Day

Were he to have definitely eaten these foods or drank these liquids, he would have contracted impurity of Rabbinic origin, as stated in Chapter 8, Halachah 10.

Were he to have definitely entered the drawn water or had the water fall upon him, he would have contracted impurity of Rabbinic origin, as stated in Chapter 9, Halachah 1.

Since only a question of Rabbinic Law is involved, we rule leniently when a doubt arises.

I.e., a question arose whether or not it contracted impurity and, hence, its status is held in abeyance. It is neither burnt as is impure terumah, nor eaten as is pure terumah.

E. g., gentiles, false deities, wine used for libations to false deities and the like.

I.e., a beit hapras and the earth of the Diaspora are not inherently impure. They were deemed impure only because the possibility existed that a piece of the bone of a corpse could be present.

Chapter 13, Halachah 13.

See Chapter 13, Halachah 1.

E. g., perhaps they came in contact with the clothes of an ordinary person [the Rambam’s Commentary to the Mishnah (Taharot 4:12)].

I.e., a zav or the like who may not partake of sacrificial foods until he offers the sacrifices associated with his emergence from impurity.

She discharged fluid and it could not be determined whether it was blood or not.

I.e., she miscarried and it could not be determined whether the fetus was of sufficient maturity to require that she bring a sacrifice for her purification.

Hilchot Mechusrei Kapparah 1:10. The same concepts apply to all others who must bring sacrifices before regaining purity.

I.e., Hilchot Tum’at Tzara’at 6:5.

If it were certain that the pure person passed under the tree, he would be impure (Hilchot Tzara’at 10:12).

If a person afflicted with tzara’at merely passes under a tree and does not stop there, he does not impart impurity to the persons or objects under the tree (ibid.).

I.e., if a pure object is found touching a source of impurity, it is impure; if not, its status does not change. Conversely, if a source of impurity is found touching a pure object, it imparts impurity; otherwise, it does not.

Our translation is based on the Rambam’s Commentary to the Mishnah (Chulin 3:3).

This applies even if such a situation occurs in a private domain.

As long as a crawling animal is alive, it does not impart impurity.

Since the impurity is being carried, it is considered analogous to impurity that is thrown and the principles mentioned in the previous halachah apply.

I.e., the final clause when the question was whether the crawling animal was alive.

For the status of the crawling animal is determined based on its state at the time it was discovered.

The rationale is that until the time that it is discovered to have died, it is considered as alive and therefore not a source of impurity.

Since it is known that the carcass will not remain in the mouth of the animal carrying it for an extended time, it is not considered as a fixed position.

Since they could be placed on the ground for an extended time, even though, in fact, they were placed there for a brief moment, that is sufficient, for it to be considered as a fixed position.

In the following halachah. See also Chapter 14, Halachah 3, and notes.

I.e., the ten principles mentioned in this and the previous chapter.

See Chapter 16, Halachah 2.
The Ra’avad differs with the Rambam and maintains that the Sages ruled that these ten situations are pure, even if people who have the knowledge to inquire about their status are involved. The Kessef Mishneh states that from a superficial perspective, the Ra’avad’s perspective appears justified. For, if only objects are involved, what is the difference between these ten situations and others? Since we are speaking about objects, they should be considered as pure, even when the doubt arises in a private domain. There is no need to single them out as unique. He explains that, according to the Rambam, the intent in mentioning these ten questionable situations was not to distinguish between them and others, but to illustrate the types of doubts that could arise.

For, as stated in Hilchot Tum'at Meit 1:7, moving an object is equivalent to carrying it.

I.e., imparting impurity through the convention of ohel.

I.e., if a mikveh to immerse is easily accessible, why shouldn’t the person immerse himself [the Rambam’s Commentary to the Mishnah (Ediot 8:4)]?

Since it was burnt, it no longer imparts impurity.

I.e., this is speaking about an instance where it is known that the garment or the needle had contracted impurity. Nevertheless, when a garment becomes worn out or a needle becomes broken or rusty, the impurity departs, because the article is not useful in its present state (see Hilchot Keilim, ch. 6). Since the garments and the needle were discovered when they were no longer useful, we assume that they were in this condition when they came into contact with the other keilim.
In his Commentary to the Mishnah (Taharot 3:5, 9:9, according to Rav Kapach’s translation), the Rambam offers a different interpretation, stating that this is speaking about an instance where it was not known whether the garment or the needle came into contact with impurity before becoming worn, broken, or rusty or not. Were it to have come into contact with the impurity before reaching that state, it would have contracted impurity and, in the case of the needle, remained impure even after it became unfit for use. However, if it came into contact with the impurity after it became unfit for use, it would not contract impurity.

For a person’s word is accepted regarding his own status more than that of 100 witnesses (Keritot 12b).

I.e., because of the doubt involved, he should immerse in a mikveh before touching foods or keilim that are ritually pure.

For this is considered like a doubt that arises in a private domain. And we follow the principle (Halachah 8), when a doubt arises in a private domain, the object is considered as pure.

For this is considered like a doubt that arises in a public domain.