٧- مُحَمَّدُ بْنُ يَحْيَى عَنْ بَعْضِ أَصْحَابِهِ عَنِ الْحُسَيْنِ بْنِ الْحَسَنِ عَنْ حَمَّادٍ عَنْ أَبِي عَبْدِ اللهِ (عَلَيْهِ السَّلام) قَالَ يُكْرَهُ أَنْ يُشْتَرَى الثَّوْبُ بِدِينَارٍ غَيْرَ دِرْهَمٍ لأنَّهُ لا يُدْرَى كَمِ الدِّينَارُ مِنَ الدِّرْهَمِ. 
7. Muhammad ibn Yahya has narrated from certain persons of his people from al-Husayn ibn al-Hassan from Hammad who have said the following: “Abu ‘ Abd Allah , has said, ‘It is undesirable to buy something with dinar which is other than (a particular) dirham because he does not know the value of dinar in relation to the dirham.’” 