Al-Kāfi - Volume 1 > Chapter on the Qualities of the Scholars
Hadith #2

2ـ عَلِيُّ بْنُ إِبْرَاهِيمَ عَنْ مُحَمَّدِ بْنِ عِيسَى عَنْ يُونُسَ عَنْ حَمَّادِ بْنِ عُثْمَانَ عَنِ الْحَارِثِ بْنِ الْمُغِيرَةِ النَّصْرِيِّ عَنْ أَبِي عَبْدِ الله (عَلَيْهِ السَّلام) فِي قَوْلِ الله عَزَّ وَجَلَّ إِنَّما يَخْشَى الله مِنْ عِبادِهِ الْعُلَماءُ قَالَ يَعْنِي بِالْعُلَمَاءِ مَنْ صَدَّقَ فِعْلُهُ قَوْلَهُ وَمَنْ لَمْ يُصَدِّقْ فِعْلُهُ قَوْلَهُ فَلَيْسَ بِعَالِمٍ.

2. Ali ibn Ibrahim has narrated from Muhammad ibn ‘Isa from Yunus from Hammad ibn ‘Uthman from al-Harith ibn Mughirah al-Nasri from abu ‘Abdallah (a.s.) about the words of Allah, the Most Majestic, the Most gracious. “Only God’s knowledgeable servants fear Him . ..”, (35:28) that scholars are those whose deeds would testify to the truthfulness of their words, otherwise, they are not scholars.’”