What does Genesis 20:8 mean?
Abimelech, king of Gerar, has taken Abraham's wife Sarah for his own wife. Abraham had said plainly that Sarah was his sister. Abimelech believed him. Apparently, some time passed during which God kept all of the women in Abimelech's household from bearing children and during which Abimelech, and possibly others, had become very ill (Genesis 20:17–18).The previous verses describe a conversation between God and Abimelech in a dream. God said Abimelech would die for taking away another man's wife (Genesis 20:3). Abimelech said, truthfully, that he didn't know Sarah was married, and he had not yet touched her (Genesis 20:4–5). God agreed, stating that Abimelech and his household would live if he would return Sarah to Abraham and Abraham would pray for them (Genesis 20:6–7).
Now Abimelech gets up early in the morning and tells all his servants about the dream. Everyone is afraid. They believe, apparently, that God will do as He says. Their fear of God demonstrates more faith in Him than Abraham's fearful lie to Abimelech.