As-Salam in buying a she-camel to be delivered after it has given birth Sahih al-Bukhari 2256
Arabic hadith text
حَدَّثَنَا مُوسَى بْنُ إِسْمَاعِيلَ، أَخْبَرَنَا جُوَيْرِيَةُ، عَنْ نَافِعٍ، عَنْ عَبْدِ اللَّهِ ـ رضى الله عنه ـ قَالَكَانُوا يَتَبَايَعُونَ الْجَزُورَ إِلَى حَبَلِ الْحَبَلَةِ، فَنَهَى النَّبِيُّ صلى الله عليه وسلم عَنْهُ.فَسَّرَهُ نَافِعٌ أَنْ تُنْتَجَ النَّاقَةُ مَا فِي بَطْنِهَا
Translation
Narrated `Abdullah
The people used to sell camels on the basis of Habal-al-Habala. The Prophet (ﷺ) forbade such sale. Nafi` explained Habal-al-Habala by saying. "The camel is to be delivered to the buyer after the she-camel gives birth."