Комментарий к Берешит 12:16

ולאברם הטיב בעבורה AND TO ABRAM HE DEALT WELL — he means Pharaoh — בעבורה FOR HER SAKE.

ולאברם היטיב בעבורה, as soon as the king had taken Sarai he showered Avram with favours, seeing that she had described him as her brother. The favours consisted of the king sending him livestock, as well as other gifts which he could enjoy personally, so that he would give his consent to the marriage. Afterwards, when he had been punished by G’d, he did not ask Avram for forgiveness but deported him, as opposed to Avimelech (Genesis 20,14) The meaning of the words

ותקח האשה ולאברם היטיב, the members of Pharaoh’s household did not even waste time to seduce Sarai but abducted her forcefully. They thought that seeing that it was a compliment for Sarai to be desired by the king himself, she would automatically consent to such an elevation of her status. Seeing that she had described herself only as Avram’s sister and not his wife, they had no reason to believe that there was a legal obstacle to such a union. Pharaoh himself said “I took her as a wife for myself,” not a concubine, not a mistress. In verse 19 he explains that he had taken Sarai as a wife, feeling certain that she was not legally linked to any other man.