(1) Some time afterward, God put Abraham to the test—saying to him, “Abraham.” He answered, “Here I am.” (2) “Take your son, your favored one, Isaac, whom you love, and go to the land of Moriah, and offer him there as a burnt offering on one of the heights that I will point out to you.”

(1) AND G-D TRIED ABRAHAM. The matter of “trial,” in my opinion, is as follows: Since a man’s deeds are at his absolute free command, to perform them or not to perform them at his will, on the part of one who is tried it is called “a trial.” But on the part of the One, blessed be He, who tries the person, it is a command that the one being tested should bring forth the matter from the potential into actuality so that he may be rewarded for a good deed, not for a good thought alone.
Know further that G-d trieth the righteous (Psalms 11:5), for knowing that the righteous will do His will, He desires to make him even more upright, and so He commands him to undertake a test, but He does not try the wicked, who would not obey. Thus all trials in the Torah are for the good of the one who is being tried.

(21) Thus said GOD of Hosts, the God of Israel: Add your burnt offerings to your other sacrifices and eat the meat! (22) For when I freed your ancestors from the land of Egypt, I did not speak with them or command them concerning burnt offerings or sacrifice. (23) But this is what I commanded them: Do My bidding, that I may be your God and you may be My people; walk only in the way that I enjoin upon you, that it may go well with you. (24) Yet they did not listen or give ear; they followed their own counsels, the willfulness of their evil hearts. They have gone backward, not forward,

[Trans DR] One ought to explain this as follows: The essential mitzvah did not relate to burnt offerings and peace offerings--"Do my bidding so that you may be My people." It was on that condition that He gave them the Torah. The Ten Commandments, which encapsulate the entire Torah, do not hint at burnt offerings or peace offerings. Even when He spoke about offerings, He did not command them to bring offerings. Rather, "When any of you presents an offering" (Leviticus 7:2)--if one chooses to do so voluntarily, one should offer it in the following way. The Daily Offerings which He ordained honored the Temple and came from the community. He did not bid individuals to bring offerings in the way He bid them to act justly and to perform the other commandments. An individual was commanded to bring an offering only if he sinned inadvertently. ...

(22) Aaron lifted his hands toward the people and blessed them; and he stepped down after offering the purgation offering, the burnt offering, and the offering of well-being. (23) Moses and Aaron then went inside the Tent of Meeting. When they came out, they blessed the people; and the Presence of GOD appeared to all the people. (24)Fire came forth from before GOD and consumed the burnt offering and the fat parts on the altar. And all the people saw, and shouted, and fell on their faces.

(1) ויברכם AND HE BLESSED THEM with the priestly benediction (Numbers 6:24—26): “May the Lord bless thee … May the Lord cause his face to shine … May the Lord lift up …” (cf. Sifra, Shemini, Mechilta d'Miluim 2 17; Sotah 38a)

(8) The seventh question: We see that the sanctification of the Sanctuary and Altar was effected by the descent of fire from Heaven upon the Altar, which consumed the offerings. The people saw and shouted and fell on their faces (cf. Leviticus 9:24). A similar passage appears in connection with Solomon's Temple: "When Solomon finished praying, fire descended from heaven and consumed the burnt offering and the sacrifices... All the Israelites witnessed the descent of the fire and the glory of the Lord on the House; they knelt with their faces to the ground and prostrated themselves, praising the Lord, 'For He is good, for His steadfast love is eternal.'" (2 Chronicles 7:1-3). So in the days of Elijah the sanctification of God was effected by fire: "...the god who responds with fire, that one is God." (1 Kings 18:24). Therefore, it is appropriate to ask, why was the divine sanctification effected by fire and not by water or something else?

(17) ...The Holy One Blessed be He desired to sanctify His Altar and His Tabernacle through the descent of the divine fire there for four reasons: 1) The divine Camp and the collective of his angels is always likened to fire, as it is written, "the appearance of the Presence of the Lord was like a consuming fire" (Exodus 24:17). Ezekiel beheld his prophecy with fire, as it is written, "flashing fire...and in the center of it, in the center of the fire, a gleam as of amber" (Ezekiel 1:4). And Daniel said, "His throne was tongues of flame; its wheels were blazing fire. A river of fire..." (Daniel 7:9-10). Since the divine camp is called 'fire' in the words of the prophets, fire came to the Tabernacle and to the Temple to indicate that the Divine Presence and Glory of the Lord were there with the holy myriads. ... 2) The human intellect doubts the divine Providence due to the exalted nature of the Provider and the lowliness mortal individuals. He, may He be blessed, is non-corporeal and does not have accidents that would allow humans to perceive Him. Therefore, in order to ingrain the truth of his Providence in the minds of His servants, together with His exalted status, God brought fire down from heaven onto the altar... 3) The divine Torah is likened to fire, as it is written, "Lightning [אש] flashing from His right" (Deuteronomy 33:2). The prophet said, "Behold, My word is like fire" (Jeremiah 23:29). Once the Tabernacle was completed and Israel [had brought] their offerings, fire descended from Heaven to express that the true perfection consists in keeping the Torah that is likened to fire, as it was granted from Heaven. 4) Israel were in deep doubt about how the offerings could be of 'pleasant odor' to the Name, since He is distinct from all physicality. Therefore, He needed to bring down fire from Heaven to consume the burnt offering and the fats so that all the people could see with their own eyes that God was pleased with their actions...

(1) Now Aaron’s sons Nadab and Abihu each took his fire pan, put fire in it, and laid incense on it; and they offered before GOD alien fire—which had not been enjoined upon them. (2) And fire came forth from GOD and consumed them; thus they died by GOD’s will.

(8) And GOD spoke to Aaron, saying: (9) Drink no wine or other intoxicant, you or your sons, when you enter the Tent of Meeting, that you may not die. This is a law for all time throughout the ages, (10) for you must distinguish between the sacred and the profane, and between the impure and the pure; (11) and you must teach the Israelites all the laws that GOD has imparted to them through Moses.

(1) ותצא אש AND THERE WENT OUT FIRE — Rabbi Eleizer said: the sons of Aaron died only because they gave decisions on religious matters in the presence of their teacher, Moses (Sifra, Shemini, Mechilta d'Miluim 2 32; Eruvin 63a). Rabbi Ishmael said: they died because they entered the Sanctuary intoxicated by wine. You may know that this is so, because after their death he admonished those who survived that they should not enter when intoxicated by wine (vv. 8—9). ...

(1) GOD spoke to Moses and Aaron, saying to them: (2) Speak to the Israelite people thus:
These are the creatures that you may eat from among all the land animals: (3) any animal that has true hoofs, with clefts through the hoofs, and that chews the cud—such you may eat.

(44) For I the ETERNAL am your God: you shall sanctify yourselves and be holy, for I am holy. You shall not make yourselves impure through any swarming thing that moves upon the earth. (45) For I the ETERNAL am the One who brought you up from the land of Egypt to be your God: you shall be holy, for I am holy. (46) These are the instructions concerning animals, birds, all living creatures that move in water, and all creatures that swarm on earth, (47) for distinguishing between the impure and the pure, between the living things that may be eaten and the living things that may not be eaten.

From the Parashah of Acharei Mot

(10) And regarding anyone of the house of Israel, or of the strangers who reside among them, who partakes of any blood: I will set My face against the person who partakes of the blood; I will cut them off from among their kin. (11) For the life of the flesh is in the blood, and I have assigned it to you for making expiation for your lives upon the altar; it is the blood, as life, that effects expiation. (12) Therefore I say to the Israelite people: No person among you shall partake of blood, nor shall the stranger who resides among you partake of blood.

(2) זאת החיה THESE ARE THE ANIMALS — the word חיה is an expression denoting life and is purposely used here in preference to בהמה to express the following idea: because Israel cleave to the Omnipresent and therefore deserve to remain in life, [זאת החיה is thus taken to mean: This, O living nation (or, nation that lives), is what ye may eat!]. He therefore separated them from what is unclean, and imposed commandments upon them, whilst to the other nations who do not cleave to him He prohibited nought. A parable! It may be compared to the case of a physician who goes to visit a sick person: one who is incurable he permits to eat whatever he chooses, while to the patient who may recover he gives directions as to what he may eat and may not eat — as may be found in the Midrash of Rabbi Tanchuma 3:3:6.

Consider how the prophet Ezekiel associates a kashrut issue with other violations of the relationship with God--

(25) Therefore say to them: Thus said the Sovereign GOD: Youeatwiththeblood, you raise your eyes to your fetishes, and you shed blood—yet you expect to possess the land! (26) You men have relied on your sword, you have committed abominations, you have defiled one another’s wives—yet you expect to possess the land!

(17) Blessed are You, Lord our God, King of the universe, who distinguishes between the holy and the profane, between light and darkness, between Israel and the nations, between the seventh day and the six working days. Blessed are You, O Lord, who distinguishes between the holy and the profane.