Rambam - 1 Chapter a Day

Hilchot Tum’at Meit, Chapter 5, Halachah 8.

In the Introduction to Seder Taharot in his Commentary to the Mishnah, the Rambam emphasizes that such a person is “considered like a secondary derivative,” i.e., his status is not actually that of a secondary derivative, for he has already purified himself. This is the basis for the leniencies regarding liquids mentioned later.

In Hilchot Terumah 7:2, the Rambam explains a similar concept, quoting Leviticus 22:7: “And the sun will set and he will become pure.” As mentioned in that halachah, the intent is not sunset, but the time when there is no trace of the sun’s light in the sky.

Thus the impurity is of Scriptural origin (Shabbat 14b).

The Rambam’s words here have attracted the attention of the Kessef Mishneh and others, based on the Rambam’s statements in Chapter 9, Halachah 1: “[after a person who contracted impurity in such a manner] immerses himself, he need not wait until nightfall [to regain purity], for the impurity contracted by this person is fundamentally a Rabbinic decree.”
Rambam LeAm suggests that the difficulty can be resolved on the basis of the distinction made by the Kessef Mishneh (in his gloss to Hilchot Tum’at Meit 5:5; Hilchot Ishut 1:1, et al) that the Rambam is depending on his thesis (see Sefer HaMitzvot, General Principle 2) that any concept that is not explicitly stated in the Torah is considered as “from the Oral Tradition” even though it was also conveyed to Moses at Sinai and derived from accepted rules of Biblical exegesis.
Thus there are two types of Rabbinic laws: those communicated by the Oral Tradition and safeguards instituted by Rabbinic decree that were not part of the Sinai revelation. In this halachah, the Rambam is referring to the first category, while in Chapter 9, he is referring to the second.
There is, however, some difficulty with that explanation, because among the Rabbinic types of impurity is that of false divinities and it has no source in Scriptural Law. Instead, it is possible to explain that whenever there is an av tum’ah; a primary source of impurity, whether Scriptural or Rabbinic, it is necessary to wait until nightfall to regain purity. Whenever there is a decree of Rabbinic impurity that does not involve an av tum’ah, like in Chapter 9, one regains purity directly after immersion.

Thus such a person can impart impurity to terumah or consecrated articles. He does not, however, impart impurity to ordinary foods (Kessef Mishneh; see the following halachah).

The term posail, translated as “disqualify,” implies that the entity itself becomes impure, but it does not impart impurity to other entities (Chapter 11, Halachah 1).

See Chapter 11, Halachah 3, for clarification regarding the status of a tertiary derivative of impurity with regard to terumah.

As stated in the conclusion of the halachah, this runs contrary to the principles that generally govern liquids that contract impurity.

Seemingly, since the person is a secondary derivative of impurity, the consecrated foods he touches should be considered tertiary derivatives and thus, not only should they themselves contract impurity, they should impart impurity to other entities (see Chapter 11, Halachah 4). Nevertheless, our Sages considered the impurity of this person as being weak. Hence, it does not have sufficient power to cause an entity that it renders impure to make other entities impure (Meilah 8b).

For there is no concept of a tertiary derivative of impurity with regard to ordinary foods.

I.e., a zav, a zavah, a person who contracted tzara'at, and a woman after childbirth. These four individuals are given this title, because even after the condition which caused the impurity passes, they immerse themselves, and the day of their immersion passes, they are not pure until they bring the sacrificial offerings required of them. See Hilchot Mechusrei Kapparah 1:1.
As evident from Hilchot Metamei Mishkav UMoshav 5:4, this is referring to one of the above individuals who immersed himself and waited the appropriate time; all that is lacking is for him to bring his sacrifice. If he has not waited the appropriate time, he is considered as a primary derivative of impurity.

But not to foods that are terumah.

See Halachah 2.

Chapter 7, Halachah 5.

A nidah, a woman after childbirth and a zavah (see ibid. 1:15).

See Hilchot Metamei Mishkav UMoshav 1:14.

Who are impure by virtue of Rabbinic decree; see Chapter 8, Halachah 10.

They may, however, disqualify them as the Rambam proceeds to explain (Kessef Mishneh).

The Rambam’s wording requires some clarification. Here he is speaking about terumah, for as stated in Chapter 11, Halachah 8, these derivatives of impurity do impart impurity to consecrated liquids.

Nor do the liquids impart impurity to the pot, as implied by the first clause of the halachah.

As described in Chapter 8, Halachah 10.

Here, also, the pot does not become impure. According to the Rambam's understanding, liquids that contracted impurity from impure hands do not impart that impurity to keilim (ibid.).

I.e., there was a question whether a person contracted impurity or not. He immersed himself so that he would definitely be pure.

See Chapter 13, Halachah 9.

See Chapter 14, Halachot 1 and 11.

Chapter 8, Halachah 10.

Halachah 4.

E. g., he is a zav, contracted tzara’at, or contracted impurity through contact with a human corpse.

E. g., if he touched one of the above or touched the carcass of an animal or a crawling animal.

See the following halachah.

When coming in contact with a human corpse (see Hilchot Tum’at Meit 5:9).

When they touch a primary source of impurity (ibid.:8).

Chapter 7, Halachah 2.

Hilchot Tum’at Meit 5:6. Even if an earthenware container touches a human corpse, it does not become a primary source of impurity.

If it came into contact with a primary source of impurity.

In contrast to foods and liquids which can contract impurity to such a degree.

See Chapter 7, Halachot 1 and 5.

If touched by a person or implement that is a primary source of impurity.

The Rambam’s words have attracted the attention of the commentaries, who note that in Halachot 3 and 4 of the following chapter, he cites verses from the Torah from which the concepts are derived. The Radbaz (responsum 1557) resolves this difficulty, stating that the verses are merely asmachtaot (supports cited by the Rabbis) and the laws are Rabbinical in origin. Others have explained the issue based on the Rambam’s conception (see note 5), that concepts derived by our Sages through the principles of Biblical exegesis are considered as being “the words of the Sages.”

This applies only to terumah or sacrificial foods, as explained in the following chapter.

This applies only to sacrificial foods, as explained in the following chapter.

See Chapter 7, Halachot 1 and 5.

See Halachah 4.

See Halachot 3 and 4.