Halakhah for Numbers 19:13

Maimonides, in his commentary on the Mishnah, explains this mishnah in terms that echo our current state of knowledge. To quote the Rambam: "Hashem taught us in Numbers 19:13 that only when someone dies or when some animal dies is there a state of defilement. Even if a person be in a most terminal state, he does not cause ritual uncleanness [tum'ah]. Certainty of death is not the state associated with tum'ah; death is." The Rambam then goes on to define mefarkhes, the term that the Mishnah used for muscular tremors, or movement after decapitation. The lizard's tail moves for some time after it has been cut off from the rest of the body. This, however, also occurs to other living organisms "if the power or the source or the stimulus for movement is spread over all parts of the body. If it does not originate from a central point, then that is not a sign of life." The Rambam here is accurately describing the difference between the localized response of a muscle group to stimulus with the functioning of a central nervous system that integrates all parts of the body.

That He prohibited any impure person from entering the Sanctuary (the Tabernacle) - and everything that is similar to it for [all] the generations: All of the courtyard and from the Gate of Nikanor onwards, which is the courtyard of the Israelites. And that is His, may He be exalted, saying, "so that they shall not render their camp impure" (Numbers 5:3). And in the Gemara, Makkot (Makkot 14b), they said, "One who entered the Temple [while] impure - a punishment is written and a prohibition is written: The punishment - 'he has rendered impure the Tabernacle of the Lord, and that soul shall be excised' (Numbers 19:13). The prohibition - 'so that they shall not render their camp impure.'" And in the Mekhilta: "'Command the Children of Israel to send away from the camp' - is with a positive commandment. But from where [do we know] it is [also] with a negative commandment? You can say, 'so that they shall not render their camp impure.'" And the prohibition about this content has already been repeated with different language; and that His, may He be exalted, saying about a woman who has given birth, "and she shall not come into the sanctuary" (Leviticus 12:4). And in the [Sifra] (Sifra, Tazria Parashat Yoledet, Section 1:1), they said, "Because it is stated (Leviticus 15:31), 'And you shall separate the Children of Israel,' I would understand - whether [one enters] from its front or from its back and he is impure, he is liable. [Hence] we learn to say, 'and she shall not come into the sanctuary.'"And there it is explained that the law of a woman who has given birth and the law of other impure people is the same with regards to this. And they [also] said in the [Sifra] (Sifra, Acharei Mot, Chapter 12:13-14), about His saying "But if he does not wash and does not bathe his body" (Leviticus 17:16), "How is this? For [failure in] the bathing of his body, the punishment is excision, but for [failure in] the washing of his clothes, it is with forty [lashes]. And from where [do we know] that it is speaking here of his rendering the sanctuary and its consecrated objects impure? It prohibited and punished, etc." Behold it has been made clear that one who transgresses this negative commandment - if he was intentional, he is punished with excision; and if he was inadvertent, he must bring a variable offering, as we explained in Commandment 72 of the Positive Commandments. And the regulations of this commandment have already been explained at the beginning of Shevuot and in Horayot. (See Parashat Nasso; Mishneh Torah, Admission into the Sanctuary 3.)

That an impure person not enter the entire Temple: That any impure person is prevented from entering the entire Temple - the likeness of which in the [future] generations is all of the yard from Nikanor Gate and inwards, which is the beginning of the yard of the Israelites - as it is stated (Numbers 5:3), "and they will not render your camps impure" - meaning to say the camp of the Divine Presence. And the proof of this being among the negative commandments is that which they, may their memory be blessed, said in the Gemara (Makkot 14b), "One who enters the Temple while impure [is liable for excision], as both the punishment and the warning are written [in the Torah.] The punishment is written (Numbers 19:13) 'the Tabernacle of God he has defiled and he shall be cut off.' The warning is written (Numbers 5:3) 'and they will not render your camps impure.'" And they also said in the Mekhilta (Sifrei Zuta on Bamidbar 5:3), "'Command the Children of Israel, and they shall send from the camp' - [that is] a positive commandment. From where do we derive [the] negative commandment? Since it is written, 'and they will not render your camps impure.'" And they said in Sifra (Sifra, Tazria Parashat Yoledet, Section 1 1), "Since it is stated (Leviticus 15:31), 'And you shall separate the children of Israel from their uncleanliness[...],' I might understand, whether from its midst or from its back," meaning to say that one who approaches the Temple from its back while he is impure would be liable for excision; "it is, therefore, written in respect to a yoledet (a woman after childbirth) (Leviticus 12:4), 'and into the sanctuary she shall not come,'" meaning to say the expression of coming is only about one who enters from the front. And there it is elucidated that the law of a yoledet and the other [cases of] impurity are the same regarding this.