Sunnah.com reference : Book 8, Hadith 193English translation : Book 8, Hadith 1140Arabic reference : Book 8, Hadith 1129
Narrated ['Aishah (RA)]:
Sahlah (RA) daughter of Suhail (RA) came and said, "O Allah's Messenger, Salim the manumitted slave of Abu Hudhaifah lives with us in our house; and he has attained what men attain (i.e. puberty)." He said, "Suckle him so you would become unlawful to him (in marriage)."

[Reported by Muslim].
وَعَنْهَا قَالَتْ: { جَاءَتْ سَهْلَةُ بِنْتُ سُهَيْلٍ.‏ فَقَالَتْ: يَا رَسُولَ اَللَّهِ! إِنَّ سَالِمًا مَوْلَى أَبِي حُذَيْفَةَ مَعَنَا فِي بَيْتِنَا, وَقَدْ بَلَغَ مَا يَبْلُغُ اَلرِّجَالُ.‏ قَالَ: 
"أَرْضِعِيهِ.‏ تَحْرُمِي عَلَيْهِ".‏ }  رَوَاهُ مُسْلِمٌ  1‏ .‏‏1 ‏- صحيح.‏ رواه مسلم (1453)‏ (27)‏.‏