From Sahih Muslim (Hadith 3574):
This hadith has been narrated on the authority of Zuhri with the same chain of transmitters (that 'A'isha said):There came Aflah, the brother of Abu'l Qulais (Allah be pleased with him), and sought permission from her, the rest of the hadith is the same (except for the words that the Holy Prophet) said:" He is your uncle. Let your hand be besmeared with dust. Abu'l Qulais was the husband of the woman who had suckled 'A'isha (Allah be pleased with her)
Reference: Muslim 3574