Genesis 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). אל שרה אשתו OF SARAH HIS WIFE — means in reference to (אֶל in sense of עַל) just as (1 Samuel 4:21) “in reference to (אל) the ark of God being taken, and in reference to (אל) her father-in-law”, where the word אל, in both cases, has the same meaning as על.

וַיֹּ֧אמֶר אַבְרָהָ֛ם אֶל־שָׂרָ֥ה אִשְׁתּ֖וֹ אֲחֹ֣תִי הִ֑וא וַיִּשְׁלַ֗ח אֲבִימֶ֙לֶךְ֙ מֶ֣לֶךְ גְּרָ֔ר וַיִּקַּ֖ח אֶת־שָׂרָֽה׃

And Avraham said of Sara his wife, She is my sister: and Avimelekh king of Gerar sent, and took Sara.