Muwatta Imam Malik Book of Business Transactions, Hadith 53

Yahya related to me from Malik that Muhammad ibn Abdullah ibn Abi Maryam asked Said ibn al-Musayyab's advice. "I am a man who buys food with receipts from al-Jar. Perhaps I will buy something for a dinar and half a dirham, and will be given food for a half." Said said, "No. You give a dirham, and take the rest in food." (A half dirham did not exist as a coin.)

حَدَّثَنِي يَحْيَى، عَنْ مَالِكٍ، عَنْ مُحَمَّدِ بْنِ عَبْدِ اللَّهِ بْنِ أَبِي مَرْيَمَ، أَنَّهُ سَأَلَ سَعِيدَ بْنَ الْمُسَيَّبِ فَقَالَ إِنِّي رَجُلٌ أَبْتَاعُ الطَّعَامَ يَكُونُ مِنَ الصُّكُوكِ بِالْجَارِ فَرُبَّمَا ابْتَعْتُ مِنْهُ بِدِينَارٍ وَنِصْفِ دِرْهَمٍ فَأُعْطَى بِالنِّصْفِ طَعَامًا . فَقَالَ سَعِيدٌ لاَ وَلَكِنْ أَعْطِ أَنْتَ دِرْهَمًا وَخُذْ بَقِيَّتَهُ طَعَامًا .