Language:
كتاب بدء الخلق
59  
Beginning of Creation
(8)
Chapter: The characteristics of Paradise, and the fact that it has already been created
(8)
باب مَا جَاءَ فِي صِفَةِ الْجَنَّةِ وَأَنَّهَا مَخْلُوقَةٌ
Sahih al-Bukhari 3255

Narrated Al-Bara (bin Azib):

The Prophet, after the death of his son Ibrahim, said, "There is a wet-nurse for him (i.e. Ibrahim) in Paradise."

حَدَّثَنَا حَجَّاجُ بْنُ مِنْهَالٍ، حَدَّثَنَا شُعْبَةُ، قَالَ عَدِيُّ بْنُ ثَابِتٍ أَخْبَرَنِي قَالَ سَمِعْتُ الْبَرَاءَ ـ رضى الله عنه ـ عَنِ النَّبِيِّ صلى الله عليه وسلم قَالَ لَمَّا مَاتَ إِبْرَاهِيمُ قَالَ ‏ "‏ إِنَّ لَهُ مُرْضِعًا فِي الْجَنَّةِ ‏"‏‏.‏
Reference : Sahih al-Bukhari 3255
In-book reference : Book 59, Hadith 65
USC-MSA web (English) reference : Vol. 4, Book 54, Hadith 477
  (deprecated numbering scheme)