Avarice

Remember that a miser is not only one who does not share a portion of his wealth with those in need. In fact, even such a one who hesitates in teaching others from the knowledge that Allah the Exalted has bestowed upon them is a miser. To hide one’s own knowledge and skill in view of the fact that if others learn, then our own worth will diminish, or our own profits will decrease, is equivalent to associating partners with Allah. For in such a case, the individual in question considers their knowledge and skill to be their provider and God. Similarly, a person who does not act with morality is also a miser. The giving of morals means to treat the rest of humanity with the exemplary morals that Allah the Exalted has granted an individual out of His sheer grace. As a result, the people will witness the individual’s morals and strive to develop them within themselves as well.

(Malfuzat [English], Vol. 2, p.150)