٦ـ مُحَمَّدُ بْنُ يَحْيَى عَنْ أَحْمَدَ بْنِ مُحَمَّدِ بْنِ عِيسَى عَنْ أَحْمَدَ بْنِ مُحَمَّدِ بْنِ أَبِي نَصْرٍ عَنِ الرِّضَا (عَلَيهِ السَّلام) قَالَ الإيمَانُ فَوْقَ الإسْلامِ بِدَرَجَةٍ وَالتَّقْوَى فَوْقَ الإيمَانِ بِدَرَجَةٍ وَالْيَقِينُ فَوْقَ التَّقْوَى بِدَرَجَةٍ وَلَمْ يُقْسَمْ بَيْنَ الْعِبَادِ شَيْ‏ءٌ أَقَلُّ مِنَ الْيَقِينِ. 
6. Muhammad ibn Yahya has narrated from Ahmad ibn Muhammad ibn ‘Isa from Ahmad ibn Muhammad ibn abu Nasr from al-Rida  who has said the following: “Belief is one degree higher than Islam. Piety is one degree higher than belief. Certainty is one degree higher above piety. Nothing is distributed among people so little as certainty is.” 