Sunan an Nasai
5037
Sahih+2

It was narrated from Ibn 'Umar that :The Messenger of Allah [SAW] said: "The parable of the hypocrite is that of a sheep that hesitates between two flocks, sometimes following one, and sometimes following another, not knowing which to follow

SahihAbu Ghuddah
SahihAl-Albani