What Kind of Korban was the Pesach?

And the idea is that the goal of the Thanksgiving offering is that it comes in appreciation of a miracle, as a means to tell the story of God's kindness that he graced you with. And because of this the Torah says to bring lots of loaves and gives you very little time to eat the Thanksgiving offering from all the Peace Offerings. That is, so you'll invite friends to one meal when you offer it, and you will tell the story of the miracle in front of a crowd...

(1) וזאת תורת זבח השלמים, here we are told that although the common denominator between these offerings is that they share the heading sh’lamim inasmuch as these offerings are categorized in the Talmud as קדשים קלים, ”holy things of a minor degree of sanctity,” there are differences, nuances between one type of such קדשים קלים and other types. For instance, if they involve thanksgiving the animals offerings are accompanied by breads, some of which are leavened. Granted that the underlying reason for the need to offer thanks is what our sages call the שאור שבעיסה, “the element of ego in the ‘dough,’” the aspiring human personality, by consisting predominantly of unleavened loaves this element becomes subordinate. [it must be remembered that basically, no other offering consisting of baked goods is allowed to be leavened. The author feels that if a person finds himself in an unexpectedly dangerous situation requiring a miracle to save him, this indicates that had his conduct been beyond reproach he would not first have become exposed to that danger. On a national rather than an individual level, the Purim story is an illustration of what the author means. Ed.] One of the reasons the Torah requires so many individual loaves of bread as part of the Todah sacrifice, is to enable as many people as possible to become aware of someone having been miraculously saved. The period during which these breads can be eaten is the same as the period holy things of the higher order may be eaten, i.e. only one day and one night, not like ordinary sh’lamim which may be eaten two days and one night.

After Rabbi Alexandri prayed, he would say the following:
Master of the Universe, it is revealed and known before You
that our will is to perform Your will, and what prevents us? The yeast in the dough, the evil inclination that is within every person...

The yeast in the dough - The evil inclination in our hearts which leavens/sours us

Upon loaves of leavened bread you shall offer it - The implication of the verse is that the purpose of the offering is the leavened loaves you bring with it. And because of this the Torah goes on and says "upon the sacrifice of his Peace Offering." Because of this, the leavened bread is the essence of the offering, because it is about thanking God for his peace... And that is why it ends with the reason that Chametz is the focus because it is an offering of Thanksgiving for his peace. Thanks for the peace that he was saved from distress.

(3) If his offering is a burnt offering...

(10) If his offering for a burnt offering is from the flock, of sheep or of goats, he shall make his offering a male without blemish.

(8) and Aaron’s sons, the priests, shall lay out the sections, with the head and the suet, on the wood that is on the fire upon the altar. (9) Its entrails and legs shall be washed with water, and the priest shall turn the whole into smoke on the altar as a burnt offering, an offering by fire of pleasing odor to the LORD.

Three Altars - For sprinkling the blood. But for the burning of the limbs there was no altar.

(1) That is that He commanded us to eat the lamb of the Pesach-offering on the night of the fifteenth of Nissan according to the stipulations mentioned - and that is that it is roasted, that it is eaten in one house and that is eaten with matzah and bitter herbs (maror). And that is His saying, "They shall eat the meat that night; they shall eat it roasted with fire, with matzah and with bitter herbs" (Exodus 12:8).

(2) With your blood, live ...He repeats this a second time because they were redeemed with the blood of the Passover sacrifice and the blood of circumcision (Pirke d’Rabbi Eliezer, chapter 29).

(1) There are thirty-six cases in the Torah with regard to which one who performs a prohibited action intentionally is liable to receive excision from the World-to-Come [karet]... And one is liable to receive karet for failure to fulfill the mitzva of bringing the Paschal offering and the mitzva of circumcision, which unlike the cases of prohibitions enumerated in the mishna, are positive mitzvot.