Sahih al-Bukhari, Hadith 2143

Narrated `Abdullah bin `Umar: Allah's Messenger forbade the sale called 'Habal-al-Habala which was a kind of sale practiced in the Pre- Islamic Period of ignorance. One would pay the price of a she-camel which was not born yet would be born by the immediate offspring of an extant she-camel.

حَدَّثَنَا عَبْدُ اللَّهِ بْنُ يُوسُفَ، أَخْبَرَنَا مَالِكٌ، عَنْ نَافِعٍ، عَنْ عَبْدِ اللَّهِ بْنِ عُمَرَ ـ رضى الله عنهما ـ أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم نَهَى عَنْ بَيْعِ حَبَلِ الْحَبَلَةِ، وَكَانَ بَيْعًا يَتَبَايَعُهُ أَهْلُ الْجَاهِلِيَّةِ، كَانَ الرَّجُلُ يَبْتَاعُ الْجَزُورَ إِلَى أَنْ تُنْتَجَ النَّاقَةُ، ثُمَّ تُنْتَجُ الَّتِي فِي بَطْنِهَا‏.‏

sunnah.com