Sayyiduna Ibn Abbas (may Allah be pleased with them both) said: "Why, when you heard it" [Surah An-Nur: 12], meaning why, when you heard it, did not "the believing men and believing women think well of their own selves and say: This is an obvious slander" [Surah An-Nur: 12]. The reason for this is that the Messenger of Allah (peace and blessings be upon him) sought counsel about it, and they spoke well and said: O Messenger of Allah, this is a lie and a falsehood. "The believing women" refers to Zaynab bint Jahsh, Barirah, the freed slave-woman of Sayyidah Aishah, and all the wives of the Prophet (peace and blessings be upon him); they said: This is a tremendous lie.
Hadith Referenceالمعجم الكبير للطبراني / مسند النساء / 19490
Sa'id bin Jubayr said: "Why, when you heard it" [Surah An-Nur: 12], meaning the accusation against Sayyidah Aishah and Safwan, why did you not reject it as a lie? "Did the believing men and believing women" [Surah An-Nur: 12] — since Zaynab bint Jahsh was among them — "not think well of their own selves" [Surah An-Nur: 12], meaning why did some of them not think well of others, that they had not seen this? "And say: This is an obvious slander" [Surah An-Nur: 12], meaning why did they not say that this accusation is a clear lie?
Hadith Referenceالمعجم الكبير للطبراني / مسند النساء / 19491
Qatadah said concerning this verse: "Why, when you heard it" [Surah An-Nur: 12]: you should have rejected it and said that this is a clear lie. By my life! When you hear something bad about your Muslim brother, not to tell a lie against him is better for you, and safer, than spreading it, publicising it and believing it.
Hadith Referenceالمعجم الكبير للطبراني / مسند النساء / 19492
Ibn Jurayj said concerning this verse: "Why, when you heard it, did the believing men and believing women" [Surah An-Nur: 12]: meaning some of them would say to others: Do you not listen to what he says?
Hadith Referenceالمعجم الكبير للطبراني / مسند النساء / 19493