Sahih Bukhari Volume 008, Book 078, Hadith Number 670.
Narated By Az-Zuhri : I heard 'Urwa bin Az-Zubair, Said bin Al-Musaiyab, 'Alqama bin Waqqas and 'Ubaidullah bin 'Abdullah bin 'Uqba relating from 'Aisha, the wife of the Prophet the narration of the people (i.e. the liars) who spread the slander against her and they said what they said, and how Allah revealed her innocence. Each of them related to me a portion of that narration. (They said that 'Aisha said), ''Then Allah revealed the ten Verses starting with: 'Verily! Those who spread the slander...' (24.11-21)
All these verses were in proof of my innocence. Abu Bakr As-Siddiq who used to provide for Mistah some financial aid because of his relation to him, said, "By Allah, I will never give anything (in charity) to Mistah, after what he has said about 'Aisha" Then Allah revealed: 'And let not those among you who are good and are wealthy swear not to give (any sort of help) to their kins men...' (24.22) On that, Abu Bakr said, "Yes, by Allah, I like that Allah should forgive me." and then resumed giving Mistah the aid he used to give him and said, "By Allah! I will never withhold it from him."