Mishkat al-Masabih 11 Business Transactions كتاب البيوع 51

وَعَنْ عُمَرَ رَضِيَ اللَّهُ عَنْهُ قَالَ: قَالَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ: «الذَّهَبُ بِالذَّهَبِ رِبًا إِلَّا هَاءَ وَهَاءَ وَالْوَرِقُ بِالْوَرِقِ رِبًا إِلَّا هَاءَ وَهَاءَ وَالْبُرُّ بالبُرَّ إِلَّا هَاء وهاء وَالشعِير بِالشَّعِيرِ رَبًّا هَاءَ وَهَاءَ وَالتَّمْرُ بِالتَّمْرِ رِبًا إِلَّا هَاءَ وهاء»

‘Umar reported God’s Messenger as saying, “Gold for gold is usury unless both hand over on the spot*; silver for silver is usury unless both hand over on the spot; wheat for wheat is usury unless both hand over on the spot; barley for barley is usury unless both hand over on the spot; dates for dates is usury unless both hand over on the spot.” (Bukhari and Muslim.) *”the Arabic is ha’ waha’ meaning literally “take and take”.