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.

Where is the price of Christ's betrayal foretold?
For what is all Scripture profitable?
How are the present effects and future results of chastisement contrasted?
What came out of one of the four horns of the goat?
What was Paul's manner respecting the Sabbath?
What is the first -symbol of Revelation 13:9?
What promise did Christ make concerning His coming?

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