Augustine of Hippo : Having built an altar there and called upon God, Abraham proceeded thence and dwelt in the desert and was compelled by pressure of famine to go on into Egypt. There he called his wife his sister, and he told no lie. For she was this also, because she was near of blood; just as Lot, on account of the same nearness, being his brother's son, is called his brother. Now he did not deny that she was his wife but held his peace about it, committing to God the defense of his wife's chastity and providing as a man against human wiles. If he had not provided against the danger as much as he could, he would have been tempting God rather than trusting in him. We have said enough about this matter against the calumnies of Faustus the Manichaean. At last what Abraham had expected the Lord to do took place. For Pharaoh, king of Egypt, who had taken her to him as his wife, restored her to her husband when faced with severe plague. And far be it from us to believe that she was defiled by lying with another. It is much more credible that, by these great afflictions, Pharaoh was not permitted to do this. — City of God 16.19