When reading the Noah narrative in light of this notion, it becomes clear that the Levitical law is only the continuation of a model of righteousness predating Sinai. .
The story of the flood ends with Noah sacrificing a burnt offering to the LORD. The law and stipulation for official offerings, however, is not given until Leviticus seven. Notice the meticulous, unvarying sacrificial sequencing of Genesis eight. Noah gives a burnt offering after exiting the ark. In Leviticus six and seven we find the burn offering to be a sacrifice of consecration and to acknowledge God. Some commentators suggest that, like the meal offering, the burnt offering could be one of thanksgiving. Only a righteous man could offer such an offering. .
Preceding Noah is the story of Cain and Abel in Genesis 4:1-16. Verses three and four read: .
"Cain brought of the fruit of the ground an offering to the Lord. And Abel, he also brought of the firstlings of his flock and of the fat thereof. And the Lord had respect unto Abel and unto his offering. And Cain was very wroth and his countenance fell." Herein we find the designated ordinance for sacrifice. In his commentary, Adam Clark reveals Dr. Kennicott's theory that the Hebrew הבל הוא בוא would be better translated "Abel brought it also (Clark)." In addition to a meal offering (מנחה minchah), Abel brought one of the firstlings of his flock. A sheep would be, of course, an acceptable sin offering. Furthermore, the word translated "respect" in verse four is שעה( sha'ah) which means "to regard or look at." Isaiah 1:15 states, "And when you spread forth your hands, I will hide mine eyes from you: yea, when ye make many prayers, I will not hear: Your hands are full of blood." .
Like the Israelites of Isaiah chapter one, God could not שעה (sha'ah), look at, Cain's offering. So, Cain's offering wasn't rejected because it was only a meal offering but, rather, because Cain's meal offering was not preceded by a sin offering.
