John Calvin's Commentary on the Bible - Genesis 20:12
Verse 12 12.And yet indeed she is my sister. Some suppose Sarah to have been Abraham’s own sister, yet not by the same mothers but born from a second wife. As, however, the name sister has a wider signification among the Hebrews, I willingly adopt a different conjecture; namely, that she was his sister in the second degree; thus it will be true that they had a common father, that is, a grandfather, from whom they had descended by brothers. Moreover, Abraham extenuates his offense, and draws a... read more
John Calvin's Commentary on the Bible - Genesis 20:11
Verse 11 11.And Abraham said. There are two points contained in this answer. For, first, he confesses that he had been induced by fear to conceal his marriage. He then denies that he had lied for the purpose of excusing himself. Now, although Abraham declares with truth, that he had not concealed his marriage with any fraudulent intention, nor for the purpose of injuring any one; yet he was worthy of censure, because, through fear, he had submitted, so far as he was concerned, to the... read more