Mishkat al-Masabih 11 Business Transactions كتاب البيوع 108

وَعَنْهُ قَالَ: قَالَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ: «لَا يَحِلُّ سَلَفٌ وَبَيْعٌ وَلَا شَرْطَانِ فِي بَيْعٍ وَلَا رِبْحُ مَا لَمْ يضمن وَلَا بيع مَا لَيْسَ عِنْدَكَ» . رَوَاهُ التِّرْمِذِيُّ وَأَبُو دَاوُدَ وَالنَّسَائِيُّ وَقَالَ التِّرْمِذِيُّ: هَذَا صَحِيح

He reported God’s Messenger as saying, “The proviso of a loan combined with a sale is not allowable, nor two conditions relating to one transaction, nor the profit arising from something which is not in one’s charge (An article belongs to the seller till the transaction is complete, and so long as it is still in his possession he is the one who gains any profit on it or bears any loss. The buyer cannot claim profit till he is in possession of the article nor selling what is not in your possession. Tirmidhi, Abu Dawud and Nasa’i transmitted it, Tirmidhi saying this is a sahih tradition.