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.

When purged from these sins, in what condition is a man, and for what is he prepared?
What is said of the fourth kingdom?
What was the first beast like?
That there might be no misunderstanding, what did Moses do?
10. Because the disciples plucked a few ears of corn on the Sabbath day to satisfy hunger, what accusation did the Pharisees make against them to Christ?
5. What did He say of those who should break one of the least of God's commandments, and teach men so to do?
In what condition did David expect to rise?

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