Narrated 'Amr b. Suh'aib:

On his father's authority, said that his grandfather told that the Messenger of Allah ﷺ forbade the type of transactions in which earnest money was paid.

Malik said: This means, as we think--Allah better knows-that a man buys a slave or hires an animal, and he says: I give you a dinar on condition that if I give up the transaction or hire, what I gave you is yours.

حَدَّثَنَا عَبْدُ اللَّهِ بْنُ مَسْلَمَةَ، قَالَ قَرَأْتُ عَلَى مَالِكِ بْنِ أَنَسٍ أَنَّهُ بَلَغَهُ عَنْ عَمْرِو بْنِ شُعَيْبٍ، عَنْ أَبِيهِ، عَنْ جَدِّهِ، أَنَّهُ قَالَ نَهَى رَسُولُ اللَّهِ ﷺ عَنْ بَيْعِ الْعُرْبَانِ . قَالَ مَالِكٌ وَذَلِكَ - فِيمَا نَرَى وَاللَّهُ أَعْلَمُ - أَنْ يَشْتَرِيَ الرَّجُلُ الْعَبْدَ أَوْ يَتَكَارَى الدَّابَّةَ ثُمَّ يَقُولُ أُعْطِيكَ دِينَارًا عَلَى أَنِّي إِنْ تَرَكْتُ السِّلْعَةَ أَوِ الْكِرَاءَ فَمَا أَعْطَيْتُكَ لَكَ .