Prohibition on Sacrificial Fat and Blood
Before the Bible ever explains blood as altar atonement in Leviticus 17, it has already said in Genesis that blood is bound to life. Leviticus develops a preexisting Bible theme rather than inventing it.
Where this fits in the story: Genesis 9:4 provides the pre-Sinai blood/life prohibition.
Where Scripture takes it next: Acts 15 includes abstention from blood, but its exact relationship to Leviticus 7, Leviticus 17, Genesis 9, and pagan/idolatrous food settings remains debated.