Genesis 39:9 - For Righteousness Sake

There is none greater in this house than I; neither hath he kept back any thing from me but thee, because art his wife: how then can I do this great wickedness, and sin against God?

How then can I do this great wickedness, and sin against God? There is a marked resemblance between Joseph's reason for not sleeping with Potiphar's wife and that of King Abimelech's reason for not sleeping with Sarah, Abraham's wife (Genesis 20:6). In both cases, sin was avoided for the sake of righteousness, gained through divine awareness. Man's righteousness is not only the result of human motives, for we also suffer for the sake of doing what is right.

Genesis 18:9 - The tent of the Mother of Nations.

And they said unto him, Where is Sarah thy wife? And he said, Behold, in the tent.

the tent is referring to Sarah's tent, the home of the Mother of Nations (Genesis 17: 15, 16). After Sarah dies, Rebekah successfully takes over the duties and responsibilities as the Mother of Nations (Genesis 24:67).