The eleven verses in Genesis 12: 10-20 recounts the story of Abram and his wife Sarah when they visited Egypt. In these chapters, it is described that when Abram and Sarah went to Egypt, Abram was aware that Egyptians would like Sarah. His fears were that if they knew that Sarah was his wife, they might kill Abram to take Sarah. Therefore Abraham told Sarah that when they enter into Egypt he was going to introduce Sarah as his sister.
 Good News Bible (1994): The Story of Creation (Genesis 12: 10-20)