Musannaf Ibn Abi Shayba 26:18

Waki’ narrated to us, from Musa ibn Ubaydah, from Muhammad ibn Ka’b, who said: If Allah intends good for a servant, He grants him understanding of the religion, makes him ascetic regarding the world, and gives him insight into his own faults. Whoever is given this has been given the good of the world and the Hereafter.