٩- مُحَمَّدُ بْنُ يَحْيَى عَنْ مُحَمَّدِ بْنِ الْحُسَيْنِ عَنْ عَلِيِّ بْنِ الْحَكَمِ عَنِ الْعَلاءِ عَنْ مُحَمَّدِ بْنِ مُسْلِمٍ عَنْ أَبِي جَعْفَرٍ (عَلَيْهِ السَّلام) قَالَ قُلْتُ لَهُ مَا تَقُولُ فِي الْبُرِّ بِالسَّوِيقِ فَقَالَ مِثْلا بِمِثْلٍ لا بَأْسَ بِهِ قُلْتُ إِنَّهُ يَكُونُ لَهُ رَيْعٌ أَوْ يَكُونُ لَهُ فَضْلٌ فَقَالَ أَلَيْسَ لَهُ مَئُونَةٌ قُلْتُ بَلَى قَالَ هَذَا بِذَا وَقَالَ إِذَا اخْتَلَفَ الشَّيْئَانِ فَلا بَأْسَ مِثْلَيْنِ بِمِثْلٍ يَداً بِيَدٍ.
9. Muhammad ibn Yahya has narrated from Muhammad ibn al-Husayn from Ali ibn al-Hakam from al-‘Ala’ from Muhammad ibn Muslim who has said the following: “I once asked abu Ja‘far , about his opinion on wheat and the sawiq (mush made of wheat or barley). He (the Imam) said, ‘Their exchange in equal measures is not harmful.’ I then asked, ‘What happens if one has a certain yield or preference over the other?’ He (the Imam) said, ‘Does it not have expenses and maintenance?’ I replied, ‘Yes, it has such overheads.’ He (the Imam) said, ‘This is for that.’ He (the Imam) then said, ‘If they are two different things then exchange of one for two at the same time is permissible.’” 