Sforno on Genesis 12:16/ספורנו על בראשית י״ב:ט״ז

1ותקח 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.