Quran 33.30-32
O ye wives of the Prophet! Whosoever of you committeth manifest lewdness, the punishment for her will be doubled, and that is easy for Allah. And whosoever of you is submissive unto Allah and His messenger and doeth right, We shall give her reward twice over, and We have prepared for her a rich provision. O ye wives of the Prophet! Ye are not like any other women. If ye keep your duty (to Allah), then be not soft of speech, lest he in whose heart is a disease aspire (to you), but utter customary speech.