Al-Kāfi
Hadith 14 13ـ عَلِيُّ بْنُ مُحَمَّدٍ عَنْ سَهْلِ بْنِ زِيَادٍ رَفَعَهُ قَالَ قَالَ أَمِيرُ الْمُؤْمِنِينَ (عَلَيْهِ السَّلام) الْعَقْلُ غِطَاءٌ سَتِيرٌ وَالْفَضْلُ جَمَالٌ ظَاهِرٌ فَاسْتُرْ خَلَلَ خُلُقِكَ بِفَضْلِكَ وَقَاتِلْ هَوَاكَ بِعَقْلِكَ تَسْلَمْ لَكَ الْمَوَدَّةُ وَتَظْهَرْ لَكَ الْمَحَبَّةُ.
13. Ali ibn Muhammad has narrated from Sahl ibn Ziyad in a marfu‘ manner that Amir al-Mu’mineen Ali (as) said: “Intelligence is a complete cover (protection) for one and extra knowledge and skills are evident beauty. Compensate your physical shortcomings with your extra knowledge and skills. Fight your desires with help from your intelligence and in so doing friendship is surrendered to and love becomes manifest for you.”