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 other title is given this revelation of God to man?
How definite should we be in confessing our sins?
What promise is thus fulfilled?
With what words did Daniel begin the interpretation of the dream?
What example did Christ set in Sabbath observance?
What is the measurement of the city?
In the new earth, what will he no more?

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