What is the definition of "Chelbo"?
Rashi, Ramban #1 and Targum Yonasan: It means the best part of the animal 1 - which the Pasuk immediately specifies as the fat-tail. 2
Ramban #2: The Torah first instructs the Kohanim to offer all the Cheilev of the Shelamim, then goes on to list all the parts that they need to sacrifice, both those that fall under the category of Cheilev and those that don't. 3
Targum Onkelos: It means 'its Cheilev'. Moshav Zekenim - after this, the Torah mentions all that is offered, both what is Cheilev and what is not Cheilev.
As we find in Korach, Bamidbar 18:29 and in Ha'azinu, Devarim 32:14 (Ramban).
Ramban and Moshav Zekenim: "Cheilev" is fatty membranes that peel from the animal's flesh easily. The tail is Shuman; it is closely attached to the flesh. Also, in Sh'mos 29:22, the Torah mentions "ha'Cheilev ve'ha'Alyah" (the tail is not included in "ha'Cheilev"). It says here "Chelbo ha'Alyah Temimah", because, when one removes the tail, much Cheilev comes with it. "Chelbo" cannot mean 'its Cheilev', because one may eat the tail of a Chulin animal (See Ramban who elaborates. He also cites Chulin 117b, and explains that, although the tail is considered Cheilev, the Torah only forbids Cheilev that has the same Din regarding Shor, Keves and Eiz, to preclude the tail).
Such as the Alyah, the two kidneys and the lobe of the liver (Ramban).
Why is the Alyah described as "Temimah"?
Rashi (in Chulin, 11a): Because one is not permitted to split it or to cut it in two, even in order to examine it.
Ramban: To teach us to remove it completely, because in the process, one removes areas of fat that are next to it. 1
As the Sifra explains (Ramban).
What are the the implications of "Chelbo ha'Alya"?
Zevachim, 28a: "Chelbo h'Alyah", 've'Lo Or ha'Alyah'; this teaches us that the skin of the Alyah is not considered part of the Alyah, and that, consequently, if the Kohen Shechts a Shelamim with the intention of eating the skin of the Alyah outside the Azarah, the Korban is Pasul. 1
Which it would not be if he had in mind to eat the Alyah itself outside the Azarah. See Torah Temimah, note 36.
Having said "Chelbo" ? which incorporates all th parts that go on the Mizbe'ach, why does the Torah proceed to list them independently?
Oznayim la'Torah: This is a 'K'lal u'Perat' ? one of the thirteen principles of R. Yishmael by which the Torah is expounded 1 - 'Ein bi'Chelal Ela Mah she'bi'Perat', meaning that the P'rat is merely explaining the K'lal, without adding anything.
Oznayim la'Torah: This is similar to the same type K'lal u'Perat later in 4:8. This explanation does not however, conform to the Trop, which places the word "Chelbo" together with "ha'Alyah Temimah" ? rather than with "Shelamim", as the Oznayim la'Torah suggests.
What does "le'Umas he'Atzeh" mean?
Rashi and Rashbam: It means 'above the kidneys which give advice'.
Rashi (in Tetzaveh, Sh'mos, 29:22): It means 'below the kidneys ... '.
