 ١ـ مُحَمَّدُ بْنُ الْحَسَنِ وَعَلِيُّ بْنُ مُحَمَّدٍ عَنْ سَهْلِ بْنِ زِيَادٍ عَنْ مُحَمَّدِ بْنِ عِيسَى عَنْ عُبَيْدِ الله بْنِ عَبْدِ الله الدِّهْقَانِ عَنْ دُرُسْتَ الْوَاسِطِيِّ عَنْ إِبْرَاهِيمَ بْنِ عَبْدِ الْحَمِيدِ عَنْ أَبِي الْحَسَنِ مُوسَى (عَلَيْهِ السَّلام) قَالَ دَخَلَ رَسُولُ الله (صَلَّى اللهُ عَلَيْهِ وَآلِه) الْمَسْجِدَ فَإِذَا جَمَاعَةٌ قَدْ أَطَافُوا بِرَجُلٍ فَقَالَ مَا هَذَا فَقِيلَ عَلامَةٌ فَقَالَ وَمَا الْعَلامَةُ فَقَالُوا لَهُ أَعْلَمُ النَّاسِ بِأَنْسَابِ الْعَرَبِ وَوَقَائِعِهَا وَأَيَّامِ الْجَاهِلِيَّةِ وَالاشْعَارِ الْعَرَبِيَّةِ قَالَ فَقَالَ النَّبِيُّ (صَلَّى اللهُ عَلَيْهِ وَآلِه) ذَاكَ عِلْمٌ لا يَضُرُّ مَنْ جَهِلَهُ وَلا يَنْفَعُ مَنْ عَلِمَهُ ثُمَّ قَالَ النَّبِيُّ (صَلَّى اللهُ عَلَيْهِ وَآلِه) إِنَّمَا الْعِلْمُ ثَلاثَةٌ آيَةٌ مُحْكَمَةٌ أَوْ فَرِيضَةٌ عَادِلَةٌ أَوْ سُنَّةٌ قَائِمَةٌ وَمَا خَلاهُنَّ فَهُوَ فَضْلٌ.
 1. Muhammad ibn al-Hassan has narrated from Ali ibn Muhammad from Sahl ibn Ziyad from Muhammad ibn ‘Isa from ‘Ubaudallah al-Dihqan from Durust al-Wasiti from Ibrahim ibn ‘Abd al-Hamid from abu al-Hassan Musa  who has said the following. “Once the Holy Prophet (s.a) entered the Mosque and found a group of people gathered around a man. He asked, “who is he?” It was said that he was a ‘allamah. He then asked them, “What is that? “ They replied that he is the most learned man about the genealogy, the chronology, and the history of the pre-Islamic days of darkness and the poetry of Arabs. The Imam said, ‘The holy Prophet (s.a.) then told them. “Knowledge consists of only three kinds: A strong sign, a justly enjoined obligation or an established tradition. Other then these are of the extra achievements.”’