Sahih Muslim
The Book of Prayers (Kitab Al-Salat)
Book Number: 004 / Hadith Number: 1779
'Abdullah b. Mas'ud reported Allah's Messenger (may peace be upon him) as saying: There should be no envy but only in case of two persons: one having been endowed with wealth and power to spend it in the cause of Truth, and (the other) who has been endowed with wisdom and he decides cases with the help of it and teaches it (to others).