I would have understood that Cain had committed a sin in the sacrifice as per what is written:
Genesis 4:7 If you do well, will you not be accepted? And if you do not do well, sin is couching at the door; its desire is for you, but you must master it.
-God relates not doing well, or what Cain did, in reference to sin
I think that there are alternate ways of reading the reprimand given by God (Not to discount the traditional English translation). Click the above quote’s link, if interested…
their purification was not simply a custom, but rather was according to the law of Moses
I didn’t say “merely”! “according” is a combat oriented word, designating a comparison point by point. The passage in Luke
disagrees on the subjects who must offer … so that in all honesty it can not refer to only one part of the Law, unless the version of the Law we have today is corrupt there…
KATA 'OLOS (catholic) is “according to the whole”
and KATAS-TROPHE (catastrophe) means essentially “according to the turning…” eg: turning it upside down!
(I found the reference for the firstborn male being called holy too:
That fits, perfectly, with the nature of the debt incurred in Egypt. They willingly sold themselves into slavery, although they were “already” God’s child as a nation.
Exodu 4:22 And thou shalt say unto Pharaoh, Thus saith the LORD, Israel is my son, even my firstborn
Vague Sidenote: Egypt is older than Israel, as Cain is older than Abel.
…
which is why I think it refers to Jesus and Mary when it says ‘their purification according to the law’.

It’s a reasonable speculation – but “them” is not in the law to be “accorded” with – even in English translations I am aware of, nor is it in the Septuagint Greek.
But, then, there are there multiple sacrifices in both in Luke and the Law – is this just “arbitrary” in your mind?
I wouldn’t have understood that the ripping of the placenta or the flow of blood, even if it made her unclean also made her ‘sinful’…
Definitely a woman exuding blood from the vaginal cavity –
who touches something holy – is breaking the Mosaic law. A child consecrated in the womb, would appear to be sufficient to call the child “Holy” as the Nazorite Sampson, or even John the Baptist would have been. …
But, returning to the “unclean” and “sin” issues – regarding St. Paul & Mary & women, etc.
what I need is some example wherein such a thing which is not sinful (implying guilt) is called sinful in scripture (as though the word was not referring to guilt)… I’m not sure if you’ve shown this already, I have a feeling that if you did it was one of the things I missed…
A woman is considered unclean at any time she issues blood from the vaginal cavity according to the Mosaic Law.
(eg: common sense, – Maxi pads didn’t exist to keep her fresh… ewww…bacteria-caffee`
Thank God for progress, eh? That sin is gone…)
Levit 15:19 And if a woman have an issue, and her issue in her flesh be blood, she shall be put apart seven days: and whosoever toucheth her shall be unclean until the even.
…
Levit 15:30 And the priest shall offer the one for a sin offering, and the other for a burnt offering; and the priest shall make an atonement for her before the LORD for the issue of her uncleanness.
Anything she touched at this time is also called “unclean” – the bedsheets, the chairs, etc. All of these had to be purified before being returned to service.
What sin of the Woman do you see in those passages?
That she should offer a “sin” offering?
My thought, again, is that:
Jesus was holy, Mary touched him (even if she bled) ergo, Mary broke the Law of Moses
if she conceived in blood for – as it is written:
Levit 12:4 … she shall touch no hallowed thing, nor come into the sanctuary, until the days of her purifying be fulfilled.
I want to emphasize that these laws were written to teach about the sin people had engaged in and to look forward to the messiah – eg: – the sin inciting famine which made them call themselves “Pharaoh’s servants”. Even the free Egyptians didn’t use that title until the famine bankrupted them as well.
As to a specific law, again, if a
man touch an unclean thing (the woman is called “unclean” above) this law would appear to apply to him!
Levit 5:2 Or if a soul touch any unclean thing, whether it be a carcase of an unclean beast, or a carcase of unclean cattle, or the carcase of unclean creeping things, and if it be hidden from him; he also shall be unclean, and guilty.
Random thoughts…
Rachel died in childbirth … not Jacob’s first and true wife, eg: Leah, (whom I believe bore the tribe of Levi) survived the bloody death at child-birth.
And the birth name Rachel gave to her son was “Joseph” – a name associated with the phrase “God will add to me another man child” – and Joseph married the pagan Egyptian
priest’s daughter. Clearly in a line of forbidden (taboo) practice for the Israelites – if Israel is God’s firstborn, then Egypt was offered second place – only, it sinned in it’s sacrifices.
Yet through this sexual sin – and the tribes of Joseph + Benjamin children of Rachel are NOTORIOUS for them – ultimately salvation is offered. The just are hidden under sin. St. Paul, reflecting, is also from the tribe of Benjamin.
Ahhh, Perhaps the “original sin” psalm would help clarify my position – along with Israel’s sheep?