مُوَطَّأُ مَالِكٍ
Muwatta Malik 1327
Business Transactions
وَحَدَّثَنِي عَنْ مَالِكٍ، أَنَّهُ بَلَغَهُ عَنِ الْقَاسِمِ بْنِ مُحَمَّدٍ، أَنَّهُ قَالَ قَالَ عُمَرُ بْنُ الْخَطَّابِ الدِّينَارُ بِالدِّينَارِ وَالدِّرْهَمُ بِالدِّرْهَمِ وَالصَّاعُ بِالصَّاعِ وَلاَ يُبَاعُ كَالِئٌ بِنَاجِزٍ .
Yahya related to me from Malik that he had heard that al-Oasim ibn Muhammad said, ''Umar ibn al-Khattab said, 'A dinar for a dinar, and a dirham for adirham, and a sa for a sa. Something to be collected later is not to be sold for something at hand. ' "
Arabic/English book reference: Book 31, Hadith 36