Al-Kāfi - Volume 7 > Another Chapter
Hadith #3

3- حُمَيْدُ بْنُ زِيَادٍ عَنِ الْحَسَنِ بْنِ مُحَمَّدٍ عَنْ وَهْبِ بْنِ حَفْصٍ عَنْ أَبِي عَبْدِ اللهِ (عَلَيْهِ السَّلام) قَالَ مَنْ قَالَ عَلِمَ اللهُ مَا لَمْ يَعْلَمِ اهْتَزَّ الْعَرْشُ إِعْظَاماً لَهُ.

3. Humayd ibn Ziyad has narrated from al-Hassan ibn Muhammad from Wahab ibn Hafs who has narrated the following: “Abu ‘Abd Allah, ‘Alayhi al-Salam, has said, ‘If one says, “Allah has the knowledge”, when he does not know something, the Throne of Allah vibrates as a sign of expressing His greatness.’”