Musnad Ahmad 30:696

'Abd al-Razzaq narrated to us, Ma'mar informed us, from al-Zuhri, from Ibn al-Musayyib, from Abu Hurayrah, who said: The Messenger of Allah, may Allah bless him and grant him peace, said: "The likeness of the believer is like the crop; the wind does not cease to bend it, and the believer does not cease to be afflicted by trials. And the likeness of the hypocrite is like the cedar tree; it does not shake until it is harvested."