Two Aspects Of The Firstborn

There are two verses in this weeks parsha that tell us the rights of a kohan to the first born animal.  The first is (18:15) כׇּל־פֶּ֣טֶר רֶ֠חֶם לְֽכׇל־בָּשָׂ֞ר אֲשֶׁר־יַקְרִ֧יבוּ לַֽי״י֛ בָּאָדָ֥ם וּבַבְּהֵמָ֖ה יִֽהְיֶה־לָּ֑ךְ.  The second, 3 verses later, says וּבְשָׂרָ֖ם יִהְיֶה־לָּ֑ךְ כַּחֲזֵ֧ה הַתְּנוּפָ֛ה וּכְשׁ֥וֹק הַיָּמִ֖ין לְךָ֥ יִהְיֶֽה.  These two verses describe two aspects of the bechor.  It is as the first verse describes, one of the מתנות כהונה solely because it is the first born.  The second verse tells us a second aspect to the bechor, that it has the status of kadashim.

Tosfos Zevachim 75b ד"ה בכור holds that the temurah of a bechor is eaten by the owner when it gets a blemish and one doesn’t need to give it to a kohan.  The Rambam Temurah 3:2 holds it is given to the kohan.  Seemingly, they argue if the kohan gets the bechor because of its kedusha which exists on the temurah as well or because of it being the firstborn and hence one of the מתנות כהונה, which is not so regarding the temurah.  The Or Sameach asks that in Zevachim 9a entertains a הוא אמינא that if an animal was slaughtered with the intent of having the status of bechor that it is given to the kohanim.  We see even if it isn’t a literal firstborn, as long as it has the same kedusha and status as a bechor its given to the kohanim? 

The Briskor Rav (first piece on Laws of Bechoros) suggests that Tosfos also agrees that the din of kedusha obligates one to give the bechor to the kohanim.  Tosfos holds that such a din only occurs after it is slaughtered as a korban for than it falls under the rubric of the second verse and treated as a korban.  It is when the animal is still living that Tosfos holds one must give it to the kohan only because it is a firstborn so the terumah may be kept by the owner.