When Abimelech heard that Abraham had said that Sarah was his sister, Abimelech sent for Sarah and took her.  What relation was Sarah to Abraham?  The term “sister” in the Hebrew could refer to a relative.  YeHoVaH threatens Abimelech’s life in a dream and afflicted him, his wife and his slave girls for unknowingly taking Abraham’s wife.  Abimelech declared himself as a man of integrity and his nation as a righteous nation.  YeHoVaH agrees with Abimelech as a man of integrity of heart and He kept Abimelech from sinning against Him with Sarah.