Musnad Abu Ya'la al-Mawsili 110:110

It was narrated to us by Abdullah ibn Umar ibn Aban, who said it was narrated to us by Ali ibn Hashim ibn al-Barid, from Mubarak ibn Hassan, from Ata, from Ibn Abbas, who said: It was said, "O Messenger of Allah, which of our companions is best?" He said, "He whose sight reminds you of Allah, whose speech increases you in knowledge, and whose action reminds you of the Hereafter."