Rashi: It implies that only an animal that is born naturally can be brought as a Korban, but not one that is born by caesarian section.

Rashi (in Tehilim, 69:32): It teaches us that already on the day that it is born, a calf falls under the category of 'Shor'. ¹

Rashi (in Nidah, 40b): The Torah writes "Shor O Kesev" to preclude Kil'ayim ¹ from the realm of Korbanos, adding "Eiz" to preclude a Nidmeh (Chulin, 38b). ²

R. Bachye #1 and Targum Yonasan: Because the bull represents Avraham ? who brought before Hashem a tender and fat bull (in honor of his guests), ³ the ram, Yitzchak ? in place of whom Avraham sacrificed a ram, and the lamb, Ya'akov ? who brought his father a kid-goat. ⁴

R. Bachye #2: The ox is stalked by the lion, the lamb by the wolf and the goat by the leopard, and the Pasuk writes in Koheles 3:15 ?ve?ha?Elokim Yevakesh es Nirdaf? (Hashem seeks the one who is being chased) ?Hashem designated the ones who are chased to go on the MIzbe?ach. ⁵

Chulin, 38b: "O Kesev" precludes Kil'ayim (an animal whose mother is a sheep and whose father is a goat or vice-versa), and "O Eiz"precludes a Nidmeh ? an animal that does not resemble its mother, where a sheep gave birth to a baby that resembles a goat or vice-versa.

Rashi (in Tehilim, 69:32): To teach us that a calf falls under the category of 'Shor' from the day it is born.

R. Bachye: It can be compared to a king who arrived in the country and announced that whoever wants an audience with him must first see the ?Queen? ? So too, one may only bring an animal on the Mizbe?ach after it has seen the Shabbos (which is equivalent to the second ?Hey? of Hashem?s Holy Name (Malchus). ¹

Moshav Zekenim #1 (citing the Rosh) and Ba?al ha?Turim: If one offers it during the first six days, it creates the impression that one is offering it to whatever was created on the equivalent day of the creation - Shamayim and Aretz, the firmament, the dry land, the luminaries, Sheratzim, or man. It is therefore preferable to wait seven days, to internalize that Hashem created His world in six days and rested on the seventh, and then to offer it for Him. ²

Moshav Zekenim #2 (citing R. Eliezer of Garmaiza): The ox that Adam ha'Rishon offered was on the eighth day of the Creation, Consequently, Hashem said, that, just as he offered it on the eighth day ³ , so should [all Korbanos] be accepted from the eighth day and onwards.

Targum Yonasan: To ensure that it is not a Nefel (a stillborn baby). And the Gemara in Shabbos 135b learns from here that an animal that lives for eight days is not a Nefel.

Oznayim la'Torah: Out of compassion ⁴ not to interfere with the love that exists between mother and child ? since the bond between a mother and a child among animals ⁵ is short-lived and is at its strongest during the first seven days. ⁶ on the Mizbe'ach

Sifra: We learn from B'chor, where the Torah writes in Mishpatim, 22:29 "ba'Yom ha'Shemini Titno Li" that it is permitted. ¹

Zevachim, 12a: The Torah writes "Vehayah Shiv'as Yamim Tachas Imo"- implying that the night of the eighth is permitted, and then "u'va'Yom ha'Shemini Vahal'ah Yeratzeh" ? implying that the night of the eighth is forbidden, to teach us that one may declare it Kadosh on the night of the eighth but may bring it on the Mizbe'ach only on the following day. ¹

Yoma, 63b: "le'Korban" ? with reference to being Makdish it, ¹ "Isheh" ? with reference to bringing it on the Mizbe'ach ² and "la'Hashem", to incorporate the Sa'ir la'Azazel ³ in the Din of Mechusar Z'man.

Chulin, 81a: Mechusar Z'man is a Lav ha'Ba mi'Kelal Asei "u'mi'Yom ha'Shemini Yeratzeh ? ", 'mi'Yom ha'Shemini, In; me'Ikara, Lo!', which is an Asei, for which no punishment is specified.

Seforno: Having discussed the blemishes that disqualify an animal from the Mizbe'ach - even though sometimes a blemished animal is worth more than its complete counterpart, and even though one would not hesitate to bring it before one's king ¹ - the Torah now discusses perfection in time, forbidding the bringing of animals before the eighth day as Korbanos, Shechting a mother and her baby on the same day and disqualifying a Korban even with the thought of eating it after its allotted time.

R. Bachye and Hadar Zekenim: To atone for the sin of the Golden Calf. It can be compared to an esteemed woman about whom word spread that she had commited adultery. After investigation and finding her innocent, the king made a feast and seated her at the head of the table, in front of himself to publicize the fact that the slander was false. Similarly, the nations derided Yisrael for the sin of the Eigel. Hashem checked however, and discovered that it was the Eirev Rav who made it. ¹ Therefore he designated the ox at the head of the Korbanos. ²

Targum Yonasan: To recall the merit of Avraham, who was the first to acknowledge the Omnipotance of Hashem and who brought 'a tender and good calf'. ³

Moshav Zekenim #1, citing the Rosh: If he offers it during the first six days, it looks like he offers to what was created that day - Shamayim and Aretz, the firmament, the dry land, the luminaries, Sheratzim, or man. Rather, wait seven days, and know that I created My world in six days and rested on the seventh, and offer it for Me.

Moshav Zekenim #, citing R. Eliezer of Garmaiza: The ox that Adam ha'Rishon offered was on day eight of the Creation, for he sinned on Erev Shabbos, and he was not allowed to transgress the first Shabbos [to offer it]. Hashem said, just like he brought on day eight ¹ , so [all Korbanos] will be accepted from day eight and onwards.