Kommentar zu Bereschit 20:2

ויאמר אברהם AND ABRAHAM SAID — This time he did not ask her consent but forcibly and against her inclination he stated that she was his sister, because she had already been taken once to Pharaoh’s house on account of this (Genesis Rabbah 52:4).

AND ABRAHAM SAID OF SARAH HIS WIFE, SHE IS MY SISTER. This was not like what happened in Egypt. There, when they entered the land, it is said that the Egyptians saw that the woman was beautiful, and they praised her to the lords and to Pharaoh,²⁷⁵Above, 12:14-15. as they were an immoral people but this king was perfect and upright, and his people were likewise good. However Abraham suspected them, and he told everyone that she was his sister.

ויאמר אבוהם אל שרה. Abraham said about Sarah, etc. This time Abraham did not ask Sarah to be the first to announce that she was Abraham's sister as he had done when they travelled to Egypt. Then he had been motivated by the ugliness of the Egyptians and the contrast with Sarah's white skin which aroused the lust of the Egyptians. The people in Geror did not look different from Abraham and Sarah. Also, their general sexual mores were superior to that of the Egyptians. Avimelech himself felt justified in challenging Abraham's deception if it were based on such suspicions. Pharaoh had not dared to ask such a question. This is also the reason that Avimelech agreed that Abraham reside in his country, something the King of Egypt could not afford to do.