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.

Whose voice had more weight with Saul than had the commandment of God?
How faithfully should parents teach the precepts and commandments of God to their children?
25. When Christ has finished His priestly mediatorial work in the heavenly sanctuary, what decree will go forth?
What besides creation were Israel to remember when they kept the Sabbath?
What was to follow the great earthquake?
Is there danger of believers losing their hold on Christ?
How perfect will be their knowledge of God?

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