민수기 18:7의 주석

עבדת מתנה [I HAVE GIVEN YOUR PRIESTHOOD UNTO YOU] AS A SERVICE OF GIFT — This means as a gift have I given it to you, [and the stranger that comes near shall die].

I GIVE YOU THE PRIESTHOOD AS A SERVICE OF GIFT. “[This means that] it shall be to you as a gift.” This is Rashi’s language, and his intention thereby is to state that it is given to you as a complete gift, [to such an extent] that [as the verse continues], a non-priest who draws near [to do the service] will be liable to be put to death [by the hand of Heaven]. The correct interpretation appears to me to be that He is saying: “and you shall perform the service of the priesthood, but it is not to be regarded by you as a burdensome task, like that imposed upon the servants of kings, but I have given you the service of a great gift through it, for glory and for splendor¹⁹⁷Ibid., 28:2. from Me.” This is similar to the interpretation of the Rabbis:¹⁹⁸Sotah 15a. “L’moshchah¹⁹⁹Further, Verse 8. — as a distinction, [so that gifts given to the priests from the offerings are to be eaten by them] in the way that kings eat.”²⁰⁰I.e., roasted in fire and eaten with mustard (Chullin 132b).

תשמרו את כהונתכם. To ensure that a non-priest, such as King Uzziah, does not enter the domain reserved exclusively for the priests.

עבודת מתנה; this relieved the ordinary Israelites from the duty to perform service, as the “gift” to do so had not been granted to them. Added to the threat of death if an Israelite would nonetheless venture to perform such service, none of them would dare do so in the future.

עבודת מתנה אתן את כהונתכם, “your priesthood as a service that is a gift.” Rashi says that the meaning is that Aaron and his descendants being priests was a gift to them from Hashem. Nachmanides feels that the meaning is that the priests should not view their priestly duties as being burdensome, but they should welcome it as one welcomes a gift, which is what it is. It is an honour for you, not a burden.

עבודת מתנה אתן את כהונתכם, “I make your priesthood a service of dedication.” The performance of the sacrificial duties which I (G’d) impose on the priests are not to be viewed as menial tasks but as a major service and a gift from Me to you. Apart from the fact that you derive your livelihood from the performance of these duties you are to consider it as an honor and glory bestowed upon you.
The reason that the Torah repeats here once more that “the stranger who approaches (unauthorized) shall die,” is because this time it is not addressed to members of other tribes but to priests who for one reason or another have become disqualified. Even Levites are subject to this warning. If we find that the prophet Samuel (a Levite, not a priest) offered a burnt-offering (Samuel I 7,9) this was an exception dictated by special circumstances. It was similar to Gideon (a member of the tribe of Menashe) who is also reported as offering a sacrifice (Judges 6,25-27). Moreover, seeing that this paragraph deals with the situation in the desert and the period when the Tabernacle had recently been erected and the firstborn had been replaced by the Levites, there is ample reason to repeat the warning once more. (Rabbi Chavell points out that the sacrifice offered by Samuel on a private altar after the destruction of he Tabernacle in Shiloh was perfectly permissible for any Israelite and that there is nothing strange about what Samuel did there although he was the first one to do so. Compare Avodah Zarah 24.
According to the Talmud Temurah 28 the night on which Gideon offered a sacrifice was historically important as no fewer than eight prohibitions were waived on that night).

As a gift. Meaning: The service which is a gift. This means that the service itself was the gift, not that the service was a consequence of the gift, in which case the gift would have been something other than the service. Accordingly the verse afterwards would have explained that the service was as a gift because “I give you the kehunah to you…” (According to this explanation "gift" would have referred to the kehunah rather than to the service) Re’m.

ולמבית לפרכת, “and to that which is beyond the dividing curtain.” We learn from here that there was an area behind the dividing curtain which served as a place where the priests could be examined as to their status as priests. (Sifri)

A service of gift: It means to say [that] the service of priesthood given to them exclusively, all [involves giving]. This is to say, giving to something else, such as the sprinkling of blood, the burning of fats and limbs, the pouring of the water and the wine. And it is only about these forms of service which are gifts, that the non-priest who approaches is liable for death. But forms of service which are not gift - meaning to say, that do not include giving, such as the removal of the ashes, which only includes the service of removal, since they remove them and put them away from the altar - do not carry a liability for death for the non-priest...

ועבדתם, priestly functions are to be carried out only by you the priests;

עבודת מתנה, “a service performed voluntarily, as a “gift;” just as accumulated gifts to the priests from the common people were distributed by lot, so lots were also drawn as to which priests would be privileged to perform which part of the Temple service. No one could arrogate to himself to determine his personal preference.

the very fact that this assignment is in the nature of a gift for you, עבודת מתנה, makes it likely that outsiders are jealous and want a share of this. This is why you have to be especially on guard (to prevent interlopers from being punished by death.)

והזר הקרב, “and a non priest or Levite who dared to approach into the sacred domain, etc.” The Torah speaks of such a stranger presuming to perform service within the Temple. Such a stranger would also be punished, even if he had been ritually pure. Even a Levite, if he had presumed to perform Temple service would be subject to the death penalty. If you were to ask that we know that Samuel the Levite is reported to have offered service in the Temple (Samuel I 7,9), this was due to an emergency.

That is that He commanded us with the process of the sin-offering sacrifice, according to the description that is mentioned - whatever sin-offering it may be. And that is His saying, "This is the law of the sin-offering" (Leviticus 6:18). And in Leviticus, it is also explained how it is offered, what is burnt from it and what is to be eaten. (See Parashat Tzav; Mishneh Torah, Sacrificial Procedure 6.)