Romans 3:20 By the law [then] is the knowledge of sin.
Q: By what law was the knowledge of sin after the resurrection of Christ?
A: The very same law that was given when it was said, Exodus 20:17 You shall not covet. The law, then, by which sin is known, is the ten commandments, and you cannot deny it!
This law says,
The seventh day is the Sabbath of the Lord your God; in it you
shall not do any work, you nor your son, nor your daughter, nor your man-servant, nor your maid-servant, nor your cattle, nor the stranger that is within your gates: For in six days the Lord made heaven and earth, the sea, and all that in them is, and rested the seventh day: wherefore the Lord blessed the Sabbath day and hallowed it."
Elihu