Hadith 2:66
Al-Hasan said that knowledge is of two kinds:
knowledge in the heart, which is the beneficial type; and knowledge on the tongue, which is God’s allegation against a human being.” Darimi transmitted it.
وَعَن الْحسن قَالَ: «الْعِلْمُ عِلْمَانِ فَعِلْمٌ فِي الْقَلْبِ فَذَاكَ الْعلم النافع وَعلم على اللِّسَان فَذَاك حُجَّةُ اللَّهِ عَزَّ وَجَلَّ عَلَى ابْنِ آدَمَ» . رَوَاهُ الدَّارمِيّ
Original Reference: Mishkat al-Masabih 270