[Machine] The Prophet ﷺ forbade the sale of "gharar". Ayub said that Yahya explained the sale of "gharar" as the strike of arrows. The sale of "gharar" includes selling a slave that will run away, selling a stray camel, selling what is inside the bellies of animals, selling dust of minerals, and selling what is inside the chests of animals except by known measure.  

نَهَى رَسُولُ اللهِ ﷺ عَنْ بَيْعِ الْغَرَرِ قَالَ أَيُّوبُ وَفَسَّرَ يَحْيَى بَيْعَ الْغَرَرِ قَالَ إِنَّ مِنَ الغَرَرِ ضَرْبَةَ الْغَائِصِ وَبَيْعُ الْغَرَرِ الْعَبْدُ الْآبِقُ وَبَيْعُ الْبَعِيرِ الشَّارِدِ وَبَيْعُ الْغَرَرِ مَافِي بُطُونِ الْأَنْعَامِ وَبَيْعُ الْغَرَرِ تُرَابُ الْمَعَادِنِ وَبَيْعُ الْغَرَرِ مَا فِي ضُرُوعِ الْأَنْعَامِ إِلا بِكَيْلٍ