Musannaf Ibn Abi Shayba 33:187

Abdullah ibn Numayr and Muhammad ibn Bishr narrated to us, they said: Zakariya ibn Abi Za'idah narrated to us, from Sa'd ibn Ibrahim, he said: Ka'b ibn Malik narrated to me, from his father, he said: The Messenger of Allah, may Allah bless him and grant him peace, said: "The likeness of the believer is like the tender stalk of a plant; the wind tilts it, throwing it down one time and straightening it another, until it dries up. And the likeness of the disbeliever is like the cedar tree, firmly rooted upon its base; nothing tilts it until its uprooting happens all at once."