Kumail ibn Ziyaad said: 'Alee ibn Abee Taalib took hold of my hand and took me off towards the desert. When we reached it, he sat down, took a deep breath and then said:

"O Kumail ibn Ziyaad! The hearts are receptacles, so the best of them is the one which preserves the best. So memorise what I say to you.
The people are of three (types): the Scholar who is rabbaanee, 1 the one learning being upon the path of salvation, and the confused rabble who follow everyone who calls out - bending along with every wind - they are not enlightened by the light of knowledge, nor do they lean upon a firm support.

Knowledge is better than wealth. Knowledge is a protection for you, whereas it is you that has to protect wealth. The zakaat of knowledge is action, whereas spending decreases wealth. And love of the Scholar is part of the Religion. Knowledge brings about obedience for the Scholar in his own lifetime and causes him to have good repute after his death, whereas the benefit of wealth ceases when it passes away. The hoarders of wealth have died even though they are still alive, whereas the Scholars remain for as long as time remains - their persons are lost, but their examples remain in the hearts.

Here, indeed here - (and he pointed to his chest) - there is knowledge, if only I could find carriers for it. But instead I have found them quick to comprehend, but not trustworthy. They use what pertains to the Religion for worldly ends. They seek to use Allaah's proofs against His Book, blindly following the people of truth, but having no insight regarding receiving it.
Doubt pierces their hearts when anything problematic arises. They are neither this nor that. They do not know where the truth lies, and if they are mistaken then they do not know why. They are ardently in love with something the true state of which they do not know - so they become a trial for others.

And indeed, the utmost good is for the one to whom Allaah grants understanding of the Religion And it is enough ignorance for a person that he does not know about his Religion. Such a person is passionately addicted to pleasures, accustomed to following desires, or is one given to amassing wealth and piling it up. Such people are not from the callers to the Religion rather they are more like the grazing cattle. And thus knowledge passes away with the passing away of those who carry it.
Oh Allaah, yes! The earth will not be without one who stands upright for Allaah, with proof - so that Allaah's proofs and clear signs are not abolished. They are the ones who are few in number, but having the most value to Allaah. With them, Allaah asserts His proofs amongst their contemporaries and cultivates them in the hearts of those similar to them. With them, knowledge assaults and comes upon the true state of affairs, so that which those accustomed to easy living find difficult therein, they find easy; and they are at home with that which causes consternation to the ignorant ones. They live in this world with their bodies, whereas their souls are attached to higher things. They are Allaah's ambassadors in His land and the callers to His Religion. Oh how I would like to see them, and I seek Allaah's forgiveness for myself and for you. If you wish then you may leave."2

1.Rabbaanee: The scholar who acts in accordance with his knowledge and has insight into the condition of the people - so that he raises them upon the primary matters of knowledge before the more detailed and difficult matters.
2. Reported by abu nu'aym in hilyatul-awliyaa (1/79-80), al-khateeb al-baghdaadee in al-faqeeh wal-mutafaqqih (1/49-50) and ibn katheer in al-bidaayah wan-nihaayah (9/47).