What you cannot do to a covenant would necessarily apply to the commandments. The commandments are just the instructions from an amalgamation of covenants. You can also have the same commandments in multiple covenants i.e. the law of pouring out blood for slaughter is in the Gen 9 covenant and the Sinai covenant of Leviticus 17.
27 Then what becomes of boasting? It is excluded. By what law? By that of works? No, but by the law of faith. 28 For we hold that a person is justified by faith apart from works prescribed by the law. 29 Or is God the God of Jews only? Is he not the God of Gentiles also? Yes, of Gentiles also, 30 since God is one; and he will justify the circumcised on the ground of faith and the uncircumcised through that same faith. 31 Do we then overthrow the law by this faith? By no means! On the contrary, we uphold the law. . . . 13 For the promise that he would inherit the world did not come to Abraham or to his descendants through the law but through the righteousness of faith. (Romans 3:1-4:13)
Romans 3:31 says positively that they “establish” https://studybible.info/strongs/G2476 the law (Sinai covenant) this is viewed as being opposed to καταργέω and “establish” is in this tense (note “law” is singular):
Based on Romans 3:31 and Galatians 3:17 it is hard to make the argument that Sinai can be λύω or καταργέω. Galatians 3:17 also says that a covenant cannot be made void G208 so to καταργέω the promise. This I think indicates that G208 has a similar meaning to καταργέω.
Romans 3:31 seems to be talking about properly interpreting the law . . . that is to say, they do not throw down Sinai but they establish it by proper interpretation since an improper interpretation would make it broken down. This idiom of interpretation only works if it is in parallel with the actual state of the law. If the law is broken down or in the process of being broken down Paul’s statements don’t make sense. The fact that it is used in this interpretive idiom can be evidenced by observing the parallels here: https://studybible.info/search-interlinear/strongs/G208 Matthew 15:6 and Mark 7:13 use G208 as an idiom for properly interpreting or practicing and Galatians 3:17 uses G208 in parallel with καταργέω
All verses are in the NRSV unless otherwise noted. The first occurrence of the word “torah” H8451 in the Bible is here:
because Abraham obeyed my voice and kept my charge, my commandments, my statutes, and my laws.” H8451
That is parallel with Deuteronomy 11:1 which uses all those words but replaces “torah” with “mishpat” (judgments) and that word “mishpat” is also used in Gen 18:19:
No, for I have chosen him, that he may charge his children and his household after him to keep the way of the Lord by doing righteousness and justice; H4941 thaso that the Lord may bring about for Abraham what he has promised him.”
We also have Moses instructing the Children of Israel in these concepts before Sinai, specifically “torah” H8451 and “choq” H2706
15 Moses said to his father-in-law, “Because the people come to me to inquire of God. 16 When they have a dispute, they come to me and I decide between one person and another, and I make known to them the statutes H2706 and instructions H8451 of God.
So there’s a parallel between Gen 26:5 and Deut 11:1 and these words are used to describe what Abraham obeyed from God and they are all used to describe what God gave the children of Israel at Sinai. In addition, the one-word “tsadaka” in Gen 18:19 that doesn’t occur in the places we already mentioned is used here:
No, for I have chosen him, that he may charge his children and his household after him to keep the way of the Lord by doing righteousness and justice; H6666 so that the Lord may bring about for Abraham what he has promised him.”
And it will be righteousness H6666 for us, if we are careful to do all this commandment before the Lord our God, as he has commanded us.’
(Deu 6:25 ESV)
In addition the word mitzvah used in Deu 6:25 is also in Gen 26:5
because Abraham obeyed my voice and kept my charge, my commandments, H4687 my statutes, and my laws.”
I’m not saying that every law in the Torah was known or followed before Sinai, the tabernacle did not exist and the levitcal priesthood was not setup so there are plenty of laws that just didn’t apply at that time. What I am arguing however is that the law does not change unless the situation changes.
The Festivals Were Setup in Genesis
In addition the word “Moed” in Genesis 1:14 can be argued to be referring to “festivals” see the following paper:
And God said, “Let there be lights in the dome of the sky to separate the day from the night; and let them be for signs and for seasons H4150 and for days and years,
Shavuot Was Celebrated by Noah
The idea that Shavuot (one of the festivals) was observed before Sinai appears early in the Dead Sea Scrolls in Jubilees according to britannica.com:
Jubilees, in its final form, was likely written about 100 BC, though it incorporates much older mythological traditions.
Here is the passage from Jubilees:
17* Therefore, it is ordained and written in the heavenly tablets that they should observe the feast of Shebuot in this month, once per year, in order to renew the is covenant in all (respects), year by year. 18* And all of this feast was celebrated in heaven from the day of creation until the days of Noah, twenty-six jubilees and five weeks of years. And Noah and his children kept it for seven jubilees and one week of years until the day of the death of Noah. And from the day of the death of Noah, his sons corrupted it until the days of Abraham, and they ate blood. 19 But Abraham alone kept it. And Isaac and Jacob and his sons kept it until your days, but in your days the children of Israel forgot it until you renewed it for them on this mountain.
20 And you, command the children of Israel so that they might keep this feast in all of their generations as a commandment to them. One day per year in this month they shall celebrate the feast, 21* for it is the feast of Shebuot and it is the feast of the first fruits. This feast is twofold and of two natures. Just as it is written and engraved concerning it, observe it. 22 This is because I have written it in the book of the first law, which I wrote for you, so that you might observe it in each of its appointed times, one day per year. And I have told you its sacrificial offering so that the children of Israel might remember them and observe them in their generations in this month one day each year.
23* And on the first of the first month and on the first of the fourth month and on the first of the seventh month and on the first of the tenth month are the days of remembrance and they are the days of appointed times in the four parts of the year. They are written and inscribed for an eternal witness. 24 And Noah ordained them for himself as feasts for eternal generations because they were a memorial for him. 25 And on the first of the first month, he was told to make an ark. And on it the land dried up, and he opened up and saw the land. 26* And on the first of the fourth month, the mouths of the deeps of the abysses which were beneath were shut. And on the first of the seventh month, all of the mouths of the depths of the earth were opened, and the water began to go down into them. 27 On the first of the tenth month the heads of the mountains appeared, and Noah rejoiced. 28 And therefore he ordained them for himself as feasts of remembrance forever, and thus they are ordained. 29 And they set them upon the heavenly tablets. Each one of them is thirteen weeks from one to another of the remembrances, from the first to the second, and from the second to the third, and from the third to the fourth. 30 And all of the days which will be commanded will be fifty-two weeks of days, and all of them are a complete year. 31 Thus it is engraved and ordained on the heavenly tablets, and there is no transgressing in a single year, from year to year.  (Charlesworth, J. H. (1985).
The Old Testament pseudepigrapha and the New Testament: Expansions of the “Old Testament” and Legends, Wisdom, and Philosophical Literature, Prayers, Psalms and Odes, Fragments of Lost Judeo-Hellenistic Works (Vol. 2, pp. 67–68). New Haven; London: Yale University Press.) (Jubilees 6.16–31)
Genesis Had the Same Dietary Laws
Changing the subject slightly there are a few places where people say Genesis implies that the dietary laws changed, one is here:
28 God blessed them, and God said to them, “Be fruitful and multiply, and fill the earth and subdue it; and have dominion over the fish of the sea and over the birds of the air and over every living thing that moves upon the earth.” 29 God said, “See, I have given you every plant yielding seed that is upon the face of all the earth, and every tree with seed in its fruit; you shall have them for food. 30 And to every beast of the earth, and to every bird of the air, and to everything that creeps on the earth, everything that has the breath of life, I have given every green plant for food.” And it was so (Gen 1:28-30)
I think this is a misconception. In Gen 1 God creates the food chain (in general) from the bottom up: Gen 1:11 (vegetation), Gen 1:20 (sea creatures and birds), Gen 1:20 (cattle and creeping things and wild animals), Gen 1:26 (humans). It even says that man shall:
“. . . have dominion over the fish of the sea and over the birds of the air and over every living thing that moves upon the earth” (Gen 1:28)
So this seems to be about God giving sustenance to all animals through his provision of plants. In addition it seems that either the accounts in Gen 1 and 2 are contradictory (since God in Gen 2 has not yet made animals at all) or that God had not actually provided animals in the garden for Adam at first. (hence Gen 1 is an account of creation overall and Gen 2 is more specific to the garden) Therefore when God says “I give you every green plant for food” he is speaking to a state where there are no animals to choose from yet so he can’t be said to imply “you can’t eat meat.” See below:
18 Then the Lord God said, “It is not good that the man should be alone; I will make him a helper as his partner.” 19 So out of the ground the Lord God formed every animal of the field and every bird of the air, and brought them to the man to see what he would call them; and whatever the man called every living creature, that was its name. 20 The man gave names to all cattle, and to the birds of the air, and to every animal of the field; but for the man there was not found a helper as his partner. (Gen 2:18-20)
There are a couple arguments against this:
1 The ESV translates 19 as “Now out of the ground the Lord God had formed every beast of the field . . .” This suggests that it is referring to the creation of animals in Gen 1
2 “I will make him a helper as his partner” actually refers to Eve and not the animals.
The problem is that “So” at the beginning of the verse connects the creation and presentation of the animals with finding a helper for Adam and that verse 18 “I will make him a helper as his partner” is parallel with verse 20 “but for the man there was not found a helper as his partner,” so we have the animals being presented as possible helpers to Adam
Also compare with:
15 The Lord God took the man and put him in the garden of Eden to till it and keep it. 16 And the Lord God commanded the man, “You may freely eat of every tree of the garden; 17 but of the tree of the knowledge of good and evil you shall not eat, for in the day that you eat of it you shall die.” (Genesis 2:15-17)
Interestingly enough the story in Genesis 2 seems to have the order of creation differently (if you try to say it is talking about the same thing that Gen 1 is and is not just talking about the garden)
. . . In the day that the Lord God made the earth and the heavens, 5 when no plant of the field was yet in the earth and no herb of the field had yet sprung up—for the Lord God had not caused it to rain upon the earth, and there was no one to till the ground; 6 but a stream would rise from the earth, and water the whole face of the ground— 7 then the Lord God formed man from the dust of the ground, and breathed into his nostrils the breath of life; and the man became a living being. 8 And the Lord God planted a garden in Eden, in the east; and there he put the man whom he had formed. 9 Out of the ground the Lord God made to grow every tree that is pleasant to the sight and good for food, the tree of life also in the midst of the garden, and the tree of the knowledge of good and evil. (Gen 2:4-9)
This shows it must be talking about specifically the land of Israel or the land around Eden, not the entire earth.
What about the dietary requirements in Gen 9:3?
Every moving thing that lives shall be food for you; and just as I gave you the green plants, I give you everything. (Genesis 9:3)
No, the context is clearly about having the power and ability to eat said animals, not about being given permission. The phrase “just as I gave you the green plants” merely means “you will have the ability to eat ALL the animals just as you have with the plants.” Obviously not all plants or animals are good to eat:
1 God blessed Noah and his sons, and said to them, “Be fruitful and multiply, and fill the earth. 2 The fear and dread of you shall rest on every animal of the earth, and on every bird of the air, on everything that creeps on the ground, and on all the fish of the sea; into your hand they are delivered. 3 Every moving thing that lives shall be food for you; and just as I gave you the green plants, I give you everything. 4 Only, you shall not eat flesh with its life, that is, its blood. 5 For your own lifeblood I will surely require a reckoning: from every animal I will require it and from human beings, each one for the blood of another, I will require a reckoning for human life.
6 Whoever sheds the blood of a human, by a human shall that person’s blood be shed; for in his own image God made humankind.
7 And you, be fruitful and multiply, abound on the earth and multiply in it.” (Gen 8:1-7)
Genesis Had Similar Sacrifices
If you don’t believe me then I ask you why did God tell Noah specifically to take extra “clean” animals on the ark and why did Noah sacrifice them? Many sacrifices require the priest who is sacrificing them to eat some of the animal. In addition the same word that is used for “clean” animals that Noah took on the ark is only used in reference to animals to talk about dietary cleanness:
46 This is the law pertaining to land animal and bird and every living creature that moves through the waters and every creature that swarms upon the earth, 47 to make a distinction between the unclean and the clean, H2889and between the living creature that may be eaten and the living creature that may not be eaten.
1 Then the Lord said to Noah, “Go into the ark, you and all your household, for I have seen that you alone are righteous before me in this generation. 2 Take with you seven pairs of all clean H2889 animals, the male and its mate; and a pair of the animals that are not clean, H2889 the male and its mate; 3 and seven pairs of the birds of the air also, male and female, to keep their kind alive on the face of all the earth. 4 For in seven days I will send rain on the earth for forty days and forty nights; and every living thing that I have made I will blot out from the face of the ground.” 5 And Noah did all that the Lord had commanded him.
Abel Drained the Blood and Separated Fat Portions
Now it is possible that the specific sacrifices that Noah gave are simply whole burnt offerings that weren’t eaten. However, offerings are elsewhere always food and it would break the pattern if Abel and Noah were offering animals that weren’t supposed to be food. In addition Abel seems to separate the fat portions from his flock, which is parallel with later laws in the Torah:
and Abel for his part brought of the firstlings of his flock, their fat H2459 portions. And the Lord had regard for Abel and his offering,
9 You shall present its fat H2459 from the sacrifice of well-being, as an offering by fire to the Lord: the whole broad tail, which shall be removed close to the backbone, the fat H2459 that covers the entrails, and all the fat H2459 that is around the entrails; 10 the two kidneys with the fat H2459 that is on them at the loins, and the appendage of the liver, which you shall remove with the kidneys. 11 Then the priest shall turn these into smoke on the altar as a food offering by fire to the Lord.
Then the priest shall turn these into smoke on the altar as a food offering by fire for a pleasing odor. All fat H2459 is the Lord’s.
Interestingly the word used for Abel’s sacrifice is also used to describe a non-bloodly sacrifice :
This means that draining the blood may have been know at this time, possibly from the law expressed in this verse:
“Only, you shall not eat flesh with its life, that is, its blood.”
Why would Abel know about this if he wasn’t eating animals? Even though this isn’t explicitly stated in Genesis we must remember that Genesis leaves a massive amount of information out of the story: let the reader investigate this on their own. Once again I don’t believe the law changes unless the situation changes since the law is good and unless the situation changes there is no reason to suggest a different law would be good. If people or animals changed in a way that was relevant to dietary laws at some points in Genesis this would be a good reason to say that maybe the dietary laws changed. However, we just don’t have the information to decide this. In addition I think I’ve found information that implies that this wasn’t the case.
Laban The Priest Avoids Becoming Unclean
There’s multitude of evidence for other laws being practiced before Sinai: Laban (a priest) avoids looking in the baggage that Rachel is sitting on when she is menstruating. This is similar to the laws of the priests of Aaron for having to purify themselves if they touch anything unclean. However, since Rachel says she cannot rise and Laban could have purified himself and continued serving as a priest the next day this particular parallel with Sinai law is weak:
34 Now Rachel had taken the household gods and put them in the camel’s saddle, and sat on them. Laban felt all about in the tent, but did not find them. 35 And she said to her father, “Let not my lord be angry that I cannot rise before you, for the way of women is upon me.” So he searched, but did not find the household gods.
The Lord spoke to Moses, saying: 2 Direct Aaron and his sons to deal carefully with the sacred donations of the people of Israel, which they dedicate to me, so that they may not profane my holy name; I am the Lord. 3 Say to them: If anyone among all your offspring throughout your generations comes near the sacred donations, which the people of Israel dedicate to the Lord, while he is in a state of uncleanness, that person shall be cut off from my presence: I am the Lord. 4 No one of Aaron’s offspring who has a leprous disease or suffers a discharge may eat of the sacred donations until he is clean. Whoever touches anything made unclean by a corpse or a man who has had an emission of semen, 5 and whoever touches any swarming thing by which he may be made unclean or any human being by whom he may be made unclean—whatever his uncleanness may be— 6 the person who touches any such shall be unclean until evening and shall not eat of the sacred donations unless he has washed his body in water.
Finally we have Exo 19:22 where priests are talked about before the laws for priests are given:
Even the priests who approach the Lord must consecrate themselves or the Lord will break out against them.”
We have many examples of the law being practiced before Sinai:
Abraham followed a parallel of the requirements in Deuteronomy 11:1. Also, all the same words were used to describe God’s laws and statutes before Sinai. In addition Moses taught the Israelites the law before Sinai.
The feasts being practiced before Sinai based on “moedim” translated as “festivals” in Genesis 1 and the book of Jubilees saying that Shavuot was kept as far back as Noah
Sacrifices in Genesis
Clean and not clean animals in Genesis
Sacrifices in Genesis that respect these distinctions
Implied dietary laws in Genesis based on the distinction of clean and not clean and the fact that Abel poured out the blood and distinguished the fat portions in his sacrifices just as the levitical priesthood did
Laws regarding priests with David and his servants eating the showbread and Tamar being ordered to be killed and burnt with fire which is the punishment for a priest’s daughter who engages in harlotry