It was narrated that Umm Fadl said:
that the Messenger of Allah said: "Breastfeeding once or twice, or suckling once or twice, does not make (marriage) unlawful." (RU)
English reference (RU): Vol. 3, Book 9, Hadith 1940 (RU)
Arabic reference (RU): Book 9, Hadith 2016 (RU)