Genesis 20:12 - Exposition

And yet indeed she is my sister . This was the second of the patriarch's extenuating pleas, that he had not exactly lied, having uttered at least a half truth. She is the daughter of my father (Terah), But not the daughter of my mother. That Sarah was the grand-daughter of Terah, i.e. the daughter of Haran, and sister of Lot, in other words, Iscah, has been maintained. That she was Terah's niece, being a brother's daughter adopted by him, has received some support (Calvin); but there seems no reason for departing from the statement of the text, that she was her husband's half-sister, i.e. Terah's daughter by another wife than Abraham's mother (Rosenmüller, Kalisch, Keil, Knobel). And she became my wife.