How early was this sacrificial system known?

Answer

"By faith Abel offered unto God a more excellent sacrifice than Cain, by which he obtained witness that he
was righteous, God testifying of his gifts." Heb. 11: 4. See Gen. 4: 3-5; 8: 20.

What prophecy foretold of the disposal of Christ's garments at the crucifixion?
What danger attends the teaching of false doctrine?
By his works what was shown to be perfect?
Who has the promise of being blessed in his doing?
With what words did God admonish Cain?
How enduring did He say the law is?
In what sense does the angel Gabriel explain John the Baptist to be the Elijah of Mal. 4: 5?

Questions & Answers are from the book Bible Readings for the Home Circle