Surah 24. An-Nur, Ayah 15

There are three things here reprobated by way of moral teaching: (1) if others speak an evil word, that is no reason why you should allow it to defile your tongue; (2) if you get a thought or suspicion which is not based on your certain knowledge, do not give it currency by giving it expression; and (3) others may think it is a small matter to speak lightly of something which blasts a person's character or reputation: in the eyes of Allah it is a most serious matter in any case, but specially when it involves the honour and reputation of pious women.