Musnad Abu Ya'la al-Mawsili 159:46

Abu Khaythama narrated to us, Jarir narrated to us, from Muhammad ibn Ishaq, from Muhammad ibn Yahya ibn Habban, from Abd al-Rahman al-A'raj, 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 tender stalk of a plant; the winds toss it about, until a wind blows upon it and lays it prostrate."