Mishkat al-Masabih 11 Business Transactions كتاب البيوع 102

وَعَنْ عَمْرِو بْنِ شُعَيْبٍ عَنْ أَبِيهِ عَنْ جَدِّهِ قَالَ: نَهَى رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ عَنْ بَيْعِ الْعُرْبَانِ. رَوَاهُ مَالِكٌ وَأَبُو دَاوُد وَابْن مَاجَه

‘Amr b. Shu’aib, on his father’s authority, said his grandfather told that God’s Messenger forbade the type of transaction in which earnest money was paid (An arrangement by which the earnest-money was treated as part of the price if the deal was completed but was retained if it was not completed). Malik, Abu Dawud and Ibn Majah transmitted it.