the Messenger of Allah forbade selling the offspring of the offspring of a pregnant animal (Habal Al-Habalah), which was a transaction practiced by the people of the Jahiliyyah, whereby a man would buy camel to slaughter, but he would wait until the she-camel had produced offspring and the offspring in her belly had then produced offspring.  

أَنَّ النَّبِيَّ ﷺ نَهَى عَنْ بَيْعِ حَبَلِ الْحَبَلَةِ وَكَانَ بَيْعًا يَتَبَايَعُهُ أَهْلُ الْجَاهِلِيَّةِ كَانَ الرَّجُلُ يَبْتَاعُ جَزُورًا إِلَى أَنْ تُنْتَجَ النَّاقَةُ ثُمَّ تُنْتَجَ الَّتِي فِي بَطْنِهَا