It is narrated from Sayyiduna Mu'awiyah (may Allah be pleased with him) that he said: I heard the Messenger of Allah (peace and blessings be upon him) say: "O people, knowledge comes only through learning, and understanding comes only through striving to understand. Whoever Allah intends good for, He grants him understanding of the religion; and among His servants, it is only the scholars who fear Him."
Hadith Referenceالمعجم الكبير للطبراني / باب الميم / 16978