The characteristics of Paradise, and the fact that it has already been created Sahih al-Bukhari 3255

Arabic hadith text
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 قَالَلَمَّا مَاتَ إِبْرَاهِيمُ قَالَ ‏"‏ إِنَّ لَهُ مُرْضِعًا فِي الْجَنَّةِ ‏"
Translation
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."