Musnad Ahmad 788:271

Yazid narrated to us, he said: Al-Jurayri informed us, from Ghunaym ibn Qays, from Abu Musa al-Ash'ari, from the Prophet, may God bless him and grant him peace, who said: "Indeed, this heart is like a feather in a wasteland of the earth, which the wind turns over from back to front." My father said: And Isma'il did not attribute it [as a direct statement of the Prophet] from al-Jurayri.