Genesis 39:7 And it came to pass after these things, that his master's wife cast her eyes upon Joseph; and she said, Lie with me. 8 But he refused, and said unto his master's wife, 9 There is none greater in this house than I; neither hath he kept back any thing from me but thee, because thou art his wife: how then can I do this great wickedness, and sin against God?
Why would Joseph call it sin, since there were not written laws anywhere. We must observe about how he came to that conclusion, based solely on it is spoken, for as was stated before, the law of God was passed down through generations by the word of mouth. Therefore, Joseph is now managing his behaviors and his choices based solely on what his dad spoke to him of God’s laws.
Such instructions should be sufficient for persons to conclude that certain behaviors are indeed sinful, because the law of God in spoken format is just as valid as if it is written. In fact, if we would receive it, the spoken format is even greater than the written one, for there have been instances where instructions were given that were contrary to law. But because the persons in question were tethered primarily to a Person, even God, they did not run the risk of disobeying His voice.
Case in point was when God told Abraham to sacrifice Isaac on mount Moriah, a spoken command that went directly contrary to everything Abraham had been taught by God on this point. There was a terrible struggle in his mind, but because he was familiar with God’s voice he chose to obey the command. The point is that in our day, there are things written by God’s prophet to our generation, which may not be plainly laid out in scripture, and thus, the question of authority will certainly surface once more.
2nd Chronicles 20:20 And they rose early in the morning, and went forth into the wilderness of Tekoa: and as they went forth, Jehoshaphat stood and said, Hear me, O Judah, and ye inhabitants of Jerusalem; Believe in the Lord your God, so shall ye be established; believe his prophets, so shall ye prosper.
May The Lord add His blessing to the study of His word. God bless!