It was narrated from Zainab bint Abi Salamah:
that the wives of the Prophet all differed with 'Aishah and refused to allow anyone with ties of breastfeeding like Salim, the freed salve of Abu Hudhaifah, to enter upon them. They said: "How do we know? That may be a concession granted only to Salim." (FR)
English reference (FR): Vol. 3, Book 9, Hadith 1947 (FR)
Arabic reference (FR): Book 9, Hadith 2023 (FR)