وَلِأَبِي دَاوُدَ: { مَنْ بَاعَ بَيْعَتَيْنِ فِي بَيْعَةٍ فَلَهُ أَوَكَسُهُمَا, أَوْ اَلرِّبَا } 1‏ .‏‏1 ‏- حسن.‏ رواه أبو داود ( 3460 )‏.‏

“If anyone makes to transactions combined in one he is entitled to take the lower price, or (it is considered) usury.”