201 Abraham traveled from there south to the Negev and settled down between Kadesh and Shur. While he was camping in Gerar, 2 Abraham said of his wife Sarah, "She's my sister."
3 But God came to Abimelech in a dream that night and told him, "You're as good as dead - that woman you took, she's a married woman." 4 Now Abimelech had not yet slept with her, hadn't so much as touched her. He said, "Master, would you kill an innocent man? 5 Didn't he tell me, 'She's my sister'? And didn't she herself say, 'He's my brother'? I had no idea I was doing anything wrong when I did this." 6 God said to him in the dream, "Yes, I know your intentions were pure, that's why I kept you from sinning against me; I was the one who kept you from going to bed with her. 7 So now give the man's wife back to him. He's a prophet and will pray for you - pray for your life. If you don't give her back, know that it's certain death both for you and everyone in your family."
8 Abimelech was up first thing in the morning. He called all his house servants together and told them the whole story. They were shocked.
Matthew Henry's Commentary on Genesis 20:1-8
Commentary on Genesis 20:1-8
(Read Genesis 20:1-8)
Crooked policy will not prosper: it brings ourselves and others into danger. God gives Abimelech notice of his danger of sin, and his danger of death for his sin. Every wilful sinner is a dead man, but Abimelech pleads ignorance. If our consciences witness, that, however we may have been cheated into a snare, we have not knowingly sinned against God, it will be our rejoicing in the day of evil. It is matter of comfort to those who are honest, that God knows their honesty, and will acknowledge it. It is a great mercy to be hindered from committing sin; of this God must have the glory. But if we have ignorantly done wrong, that will not excuse us, if we knowingly persist in it. He that does wrong, whoever he is, prince or peasant, shall certainly receive for the wrong which he has done, unless he repent, and, if possible, make restitution.