Musnad Ahmad 27:1340

Muhammad ibn Ubayd narrated to us, Ubayd Allah narrated to us, from Nafi’, from Ibn Umar, that the Messenger of Allah (peace and blessings of Allah be upon him) said: "The likeness of the hypocrite is only like the confused ewe between two flocks; it goes to this one at one time, and to this one at another time, not knowing which of them to follow."