عَنْ عَبْدِ اللَّهِ بْنِ مَسْعُودٍ رَضِيَ اللَّهُ عَنْهُ قَالَ قَالَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَآلِهِ وَسَلَّمَ إِذَا اخْتَلَفَ الْبَيِّعَانِ وَفِي لَفْظٍ وَالسِّلْعَةُ كَمَا هِيَ وَلَيْسَ بَيْنَهُمَا بَيِّنَةٌ فَالْقَوْلُ مَا يَقُولُ صَاحِبُ السِّلْعَةِ أَوْ يَتَرَادَّانِ
Narrated by Sayyiduna Abdullah bin Mas'ud (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) said: When the buyer and the seller have a dispute and neither of them has evidence (to support their claim), while the goods are still in their original condition, then the statement of the owner of the goods will be trusted, or both will return the transaction.