Al-Kāfi - Volume 1 > Chapter on the necessity to seek knowledge and the recommendations to learn
Hadith #4

4ـ عَلِيُّ بْنُ مُحَمَّدٍ وَغَيْرُهُ عَنْ سَهْلِ بْنِ زِيَادٍ وَمُحَمَّدُ بْنُ يَحْيَى عَنْ أَحْمَدَ بْنِ مُحَمَّدِ بْنِ عِيسَى جَمِيعاً عَنِ ابْنِ مَحْبُوبٍ عَنْ هِشَامِ بْنِ سَالِمٍ عَنْ أَبِي حَمْزَةَ عَنْ أَبِي إِسْحَاقَ السَّبِيعِيِّ عَمَّنْ حَدَّثَهُ قَالَ سَمِعْتُ أَمِيرَ الْمُؤْمِنِينَ يَقُولُ أَيُّهَا النَّاسُ اعْلَمُوا أَنَّ كَمَالَ الدِّينِ طَلَبُ الْعِلْمِ وَالْعَمَلُ بِهِ أَلا وَإِنَّ طَلَبَ الْعِلْمِ أَوْجَبُ عَلَيْكُمْ مِنْ طَلَبِ الْمَالِ إِنَّ الْمَالَ مَقْسُومٌ مَضْمُونٌ لَكُمْ قَدْ قَسَمَهُ عَادِلٌ بَيْنَكُمْ وَضَمِنَهُ وَسَيَفِي لَكُمْ وَالْعِلْمُ مَخْزُونٌ عِنْدَ أَهْلِهِ وَقَدْ أُمِرْتُمْ بِطَلَبِهِ مِنْ أَهْلِهِ فَاطْلُبُوهُ.

4. Ali ibn Muhammad and others have narrated from Sahl ibn Ziyad and Muhammad ibn Yahya from Ahmad ibn Muhammad ibn ‘Isa all from ibn Mahbub from Hisham ibn Salim from abu Hamza from abu Ishaq al-Subay‘i from one who narrated to him who has said the following. “I heard Amir al-Mu’minin Ali (a.s.) say, ‘O people, you must know that religion becomes complete through seeking knowledge and acting accordingly. You must know that seeking knowledge is much more urgent for you than seeking wealth. In wealth every one’s share is guaranteed. A just person has already divided the wealth among you. He and my sword guarantee you to receive your share. Knowledge, however, is stored with those who possess it. You are commanded to seek knowledge from its sources (those who possess it). You must seek knowledge.’”