In my study of the book of Job, I was confused when he purified his children and made burnt offerings for them. As there was some doubt whether or not Job was a Jew because of where he lived (in the land of Edom), how did he know about burnt offerings? In fact, how did Cain and Abel Know about offerings? I did read in Genesis 8:20 that Noah made burnt offerings. Do you think that he received a revelation about it? I enjoy your web sight and you have become my “go to” when I need help, after the Holy Spirit of course.
Some scholars believe the Book of Job was the earliest book of the Bible to be written, predating the books of Moses by many years. They say Job lived in the land of Uz during the time when Joseph was prominent in Egypt. Uz was the son of Aram who was a son of Shem, a son of Noah. In addition, the opening verses in the book tell us Job knew the Lord and lived an upright and blameless life. That means he had to understand the need to present offerings for his sins.
As for how he knew this, as soon as sin entered the creation God made a provision for dealing with it. Ultimately He would send His son to die for our sins, but in the meantime He used an innocent animal as a substitute. This was to teach man that sin brings death but the shedding of innocent blood restores life.
While there’s no clear description of Him explaining this, we can see that from the beginning man understood it. For example in Genesis 4:3 Cain brought an improper offering and it was refused. In Genesis 4:7 God told Cain that if he did what was right his offering would be accepted. This tells us Cain had been taught to bring a proper offering.
Later, the fact that Noah knew which animals were ceremonially clean (fit for offerings) and which were not is made clear in Genesis 7:2. These two glimpses show us that the sacrificial system was put in place at the time of the fall, and was merely formalized during the time when Moses and the Israelites were in the wilderness.