Musannaf Ibn Abi Shayba 26:14

Ghundar narrated to us, from Shu'bah, from Sa'id ibn Ibrahim, from Sa'id al-Juhani, from Mu'awiyah, who said: I heard the Messenger of Allah, may Allah bless him and grant him peace, say: "Whoever Allah intends good for, He grants him understanding of the religion."