What does Genesis 20:5 mean?
The conversation between God and Abimelech continues. God has said, flatly, that Abimelech would die from his current illness for taking a married woman for his wife. Abimelech responded that he had not yet had sex with Sarah. If a king had many wives and concubines, it's possible that Sarah might have been in his house for some time before he would have even approached her for the first time. Later information, regarding the barrenness of Abimelech's household, supports the idea that she had been there for quite some time (Genesis 20:17–18). Given that nothing has happened, Abimelech asks, would God kill innocent people?Now Abimelech points out that Abraham himself said that Sarah was his sister. Abraham deceived him. Not only had Abimelech not yet slept with Sarah, he had acted with integrity in his heart. At least according to Abimelech's opinion, his intentions had only ever been appropriate.
The following verses show God's response to Abimelech, demonstrating once again that God's righteousness is impeccable. The situation can be resolved, if Abimelech is willing to follow God's plan.