1) THE "HETER HANA'AH" OF "BIGDEI KEHUNAH"
OPINIONS: The Gemara teaches that a Kohen is permitted to remain dressed in the Bigdei Kehunah after he completes the Avodah. The Gemara explains that "the Torah was not given to ministering angels," but rather to humans who physically cannot remove the sanctified clothing of Bigdei Kehunah immediately upon completion of the Avodah without the passage of any time.
To what extent does this reason for permitting personal benefit from the Bigdei Kehunah apply? If a Kohen may derive personal benefit from the Bigdei Kehunah only because of the human inability to remove them immediately upon completion of the Avodah with no delay whatsoever, perhaps he must make every effort to remove the Bigdei Kehunah as quickly as possible after the Avodah. On the other hand, perhaps this reason is not to be understood in a literal manner, and the Kohen may wear the Bigdei Kehunah for a longer period of time once he is already permitted to wear them for a moment after the Avodah is completed.
(a) The BEIS HA'LEVI (4:13-14) points out that this question is the subject of dispute among the Ba'alei ha'Tosfos. The Gemara later (66a) relates that Yanai ha'Melech donned the Tzitz in front of the Chachamim. TOSFOS there asks why was he permitted to do so if the allowance to don the Bigdei Kehunah applies only for the amount of time that it takes to remove the Bigdei Kehunah. This allowance does not permit one to don the Bigdei Kehunah l'Chatchilah.
Tosfos there clearly understands that a Kohen is not permitted to wear the Bigdei Kehunah any longer than necessary.
(b) In contrast, TOSFOS in Yoma (69a) makes no mention of any limit to the amount of time which a Kohen is permitted to remain wearing the Bigdei Kehunah. Tosfos there asks merely that since the reason for the allowance is the difficulty in removing the Bigdei Kehunah without delay, the allowance does not permit a Kohen to wear the Bigdei Kehunah l'Chatchilah with no intention of performing the Avodah.
(c) RASHI later (66a) implies that there is no prohibition whatsoever against deriving benefit from the Bigdei Kehunah. Rashi apparently is bothered by a question. The logic behind the rationale that "the Torah was not given to ministering angels" is that when the Torah initially ascribed the status of Hekdesh to the Bigdei Kehunah, it left leeway for the Kohen to continue wearing the Bigdei Kehunah even after the Avodah is completed. That is, by not giving the Bigdei Kehunah the status of Hekdesh with regard to deriving personal benefit, the Torah permitted the Kohen to wear the Bigdei Kehunah after he performs the Avodah. However, since the allowance to derive personal benefit is not derived from a verse written with regard to any specific case but is an allowance that results from a circumstance that requires the item not to be Hekdesh, perhaps it is a blanket allowance that, once it applies, no longer requires any special circumstance. Why, then, are the Bigdei Kehunah considered Hekdesh at all?
Rashi answers that the Bigdei Kehunah indeed are not Hekdesh (with regard to deriving personal benefit from them) for this reason. As mentioned above, Yanai ha'Melech donned the Tzitz in the presence of the Chachamim. Rashi there asks why was he permitted to do so when it was not the time to perform the Avodah, and he answers by citing the allowance of the Gemara here. Although the Gemara here states specifically the reasoning that "the Torah was not given to ministering angels," Rashi maintains that once the Bigdei Kehunah were not sanctified in this regard, they are not considered sanctified with regard to any form of personal benefit, even personal benefit derived beyond the time of the Avodah and not for the sake of the Avodah, and even personal benefit derived intentionally (b'Mezid).
It is interesting to note that the details of the case in the Mishnah (a Kohen who is Mekadesh a woman with the Bigdei Kehunah) differ according to these three opinions. According to the view of Tosfos in Kidushin (66a), the Kohen's act of Kidushin must be done within a few minutes after he has completed the Avodah. If any more time elapses (than the time it takes for him to remove the Bigdei Kehunah), he may no longer derive benefit from them.
According to the view of Tosfos in Yoma (69a), the Kohen's act of Kidushin must take place at any time after the day's Avodah while the Kohen is still wearing the Bigdei Kehunah as a result of performing the Avodah (for he may not derive benefit from the Bigdei Kehunah unless he wore them for the Avodah).
According to Rashi, the Kohen may be Mekadesh a woman with the Bigdei Kehunah at any time, on any day.
(Rashi's explanation of the allowance to benefit from the Bigdei Kehunah may have support from the wording of the Mishnah (53b). When the Mishnah discusses the case of a Kohen who is Mekadesh a woman with an object of Hekdesh (such as Bigdei Kehunah), it makes no mention of any conditions or circumstances to which the Halachah is limited. This implies that once the allowance to benefit from the Bigdei Kehunah was given, it applies even where the initial reasoning of "the Torah was not given to ministering angels" does not apply.) (A. Kronengold)
2) THE MEANING OF "MEZID" WITH REGARD TO DERIVING PERSONAL BENEFIT FROM THE "BIGDEI KEHUNAH"
QUESTION: The Mishnah (53b) differentiates between unintentional (Shogeg) use of items of Hekdesh to be Mekadesh a woman and intentional (Mezid) use of such items. According to Rebbi Meir, when one is Mekadesh a woman b'Mezid with an item of Hekdesh the Kidushin is valid, but b'Shogeg the Kidushin is not valid. The Gemara here explains that the Mishnah refers to one who is Mekadesh a woman with Bigdei Kehunah.
The reasoning of "the Torah was not given to ministering angels" (see previous Insight) explains the difference between Mezid and Shogeg: The allowance to derive personal benefit from the Bigdei Kehunah applies only when the Kohen derives benefit even involuntarily (that is, after he has completed the Avodah, he needs a small amount of time to remove them). Similarly, an act done b'Shogeg is an act done without intention and is comparable to an act done involuntarily. In contrast, an act done b'Mezid is done intentionally and not involuntarily.
However, RASHI's explanation of "the Torah was not given to ministering angels" does not seem consistent with the Mishnah. Rashi maintains that this reasoning permits the Kohen to derive all forms of personal benefit from the Bigdei Kehunah, even b'Mezid. According to Rashi, what is the difference between one who is Mekadesh a woman with the Bigdei Kehunah b'Shogeg and one who does so b'Mezid? In both cases, the Kidushin should take effect because the Bigdei Kehunah are not considered Hekdesh with regard to deriving personal benefit.
ANSWER: The PNEI YEHOSHUA addresses this question. He points out that Rashi does not differentiate between "Shogeg" and "Mezid" but rather between "Shogeg" and "Miskaven l'Chalelan" ("he has intention to remove them from the domain of Hekdesh"). The element of "Mezid" in the act is not the person's intentional benefit from the item, but his intentional removal of the item from the domain of Hekdesh. Accordingly, in the case of a Kohen who is Mekadesh a woman with Bigdei Kehunah, the term "Mezid" does not mean "intentionally deriving benefit" but rather "intentionally removing the item from the domain of Hekdesh." (A. Kronengold.)