Musnad Abu Ya'la al-Mawsili 109:184

Narrated to us Uqbah, narrated to us Mas'adah ibn al-Yasa', from Shibl ibn 'Abbad, from 'Amr ibn Dinar, from Jabir ibn 'Abdullah, that a man came to the Prophet, may Allah bless him and grant him peace, and said: "Who among the people is the most knowledgeable?" He said: "He who gathers the knowledge of the people to his own knowledge, and every possessor of knowledge is hungry [for more]."