Sahih Muslim
Pertaining To The Charateristics Of The Hypocrites And Command Concerning Them (Kitab Sifat Al-Munafiqin Wa Ahkamihim)
Book Number: 038 / Hadith Number: 6696
Ibn Umar reported Allah's Apostle (may peace be upon him) as saying: The similitude of a hypocrite is that of a sheep which roams aimlessly between two flocks. She goes to one at one time and to the other at another time.