Sahih al-Bukhari 2256
Sahih al-Bukhari · Book 35: Sales in which a Price is paid for Goods to be Delivered Later (As-Salam) · As-Salam in buying a she-camel to be delivered after it has given birth
Narrated `Abdullah:
حَدَّثَنَا مُوسَى بْنُ إِسْمَاعِيلَ ، أَخْبَرَنَا جُوَيْرِيَةُ ، عَنْ نَافِعٍ ، عَنْ عَبْدِ اللَّهِ ـ رضى الله عنه ـ قَالَ كَانُوا يَتَبَايَعُونَ الْجَزُورَ إِلَى حَبَلِ الْحَبَلَةِ، فَنَهَى النَّبِيُّ صلى الله عليه وسلم عَنْهُ. فَسَّرَهُ نَافِعٌ أَنْ تُنْتَجَ النَّاقَةُ مَا فِي بَطْنِهَا .
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."